Respect canvas size and frame offset in webp decoder

BUG=skia:6185

Change-Id: Id543cb689a5e33b800ebbc18f4a234e78a4c4298
Reviewed-on: https://skia-review.googlesource.com/7800
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>

5 files changed, 307 insertions, 275 deletions

diff --git a/infra/bots/assets/skimage/VERSION b/infra/bots/assets/skimage/VERSION
index dec2bf5d61..2edeafb09d 100644
--- a/infra/bots/assets/skimage/VERSION
+++ b/infra/bots/assets/skimage/VERSION
@@ -1 +1 @@
-19
\ No newline at end of file
+20
\ No newline at end of file
diff --git a/infra/bots/tasks.json b/infra/bots/tasks.json
index b2c5590c64..a511eb21f2 100644
--- a/infra/bots/tasks.json
+++ b/infra/bots/tasks.json
@@ -3571,7 +3571,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3620,7 +3620,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3669,7 +3669,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3718,7 +3718,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3767,7 +3767,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3816,7 +3816,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3865,7 +3865,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3914,7 +3914,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -3963,7 +3963,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4012,7 +4012,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4061,7 +4061,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4110,7 +4110,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4159,7 +4159,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4208,7 +4208,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4257,7 +4257,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4306,7 +4306,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4355,7 +4355,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4404,7 +4404,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4453,7 +4453,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4502,7 +4502,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4551,7 +4551,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4600,7 +4600,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4649,7 +4649,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4698,7 +4698,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4747,7 +4747,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4796,7 +4796,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4845,7 +4845,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4894,7 +4894,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4943,7 +4943,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -4992,7 +4992,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5041,7 +5041,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5168,7 +5168,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5216,7 +5216,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5264,7 +5264,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5313,7 +5313,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5362,7 +5362,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5410,7 +5410,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5458,7 +5458,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5506,7 +5506,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5555,7 +5555,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5609,7 +5609,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5663,7 +5663,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5712,7 +5712,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5766,7 +5766,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5815,7 +5815,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5868,7 +5868,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5921,7 +5921,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -5970,7 +5970,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6019,7 +6019,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6068,7 +6068,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6167,7 +6167,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6215,7 +6215,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6263,7 +6263,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6311,7 +6311,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6359,7 +6359,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6407,7 +6407,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6455,7 +6455,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6503,7 +6503,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6551,7 +6551,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6599,7 +6599,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6647,7 +6647,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6695,7 +6695,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6743,7 +6743,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6791,7 +6791,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6839,7 +6839,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6887,7 +6887,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6935,7 +6935,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -6983,7 +6983,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7031,7 +7031,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7079,7 +7079,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7127,7 +7127,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7175,7 +7175,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7223,7 +7223,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7271,7 +7271,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7319,7 +7319,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7367,7 +7367,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7415,7 +7415,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7463,7 +7463,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7511,7 +7511,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7559,7 +7559,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7607,7 +7607,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7655,7 +7655,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7703,7 +7703,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7751,7 +7751,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7799,7 +7799,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -7847,7 +7847,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
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@@ -7895,7 +7895,7 @@
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@@ -7944,7 +7944,7 @@
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+          "version": "version:20"
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@@ -7993,7 +7993,7 @@
         {
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+          "version": "version:20"
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@@ -8042,7 +8042,7 @@
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@@ -8091,7 +8091,7 @@
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@@ -8140,7 +8140,7 @@
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@@ -8189,7 +8189,7 @@
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@@ -8238,7 +8238,7 @@
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@@ -8287,7 +8287,7 @@
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@@ -8336,7 +8336,7 @@
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@@ -8385,7 +8385,7 @@
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@@ -8434,7 +8434,7 @@
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@@ -8483,7 +8483,7 @@
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@@ -8532,7 +8532,7 @@
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@@ -8581,7 +8581,7 @@
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@@ -8630,7 +8630,7 @@
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@@ -8679,7 +8679,7 @@
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@@ -8728,7 +8728,7 @@
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@@ -8777,7 +8777,7 @@
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@@ -8826,7 +8826,7 @@
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@@ -8875,7 +8875,7 @@
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@@ -8924,7 +8924,7 @@
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@@ -8973,7 +8973,7 @@
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@@ -9022,7 +9022,7 @@
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@@ -9071,7 +9071,7 @@
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@@ -9120,7 +9120,7 @@
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@@ -9169,7 +9169,7 @@
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@@ -9218,7 +9218,7 @@
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@@ -9267,7 +9267,7 @@
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@@ -9316,7 +9316,7 @@
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@@ -9365,7 +9365,7 @@
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@@ -9414,7 +9414,7 @@
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@@ -9463,7 +9463,7 @@
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@@ -9512,7 +9512,7 @@
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@@ -9561,7 +9561,7 @@
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@@ -9610,7 +9610,7 @@
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@@ -9659,7 +9659,7 @@
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@@ -9708,7 +9708,7 @@
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@@ -9757,7 +9757,7 @@
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@@ -9806,7 +9806,7 @@
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@@ -9854,7 +9854,7 @@
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@@ -9902,7 +9902,7 @@
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@@ -9951,7 +9951,7 @@
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@@ -10000,7 +10000,7 @@
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@@ -10048,7 +10048,7 @@
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@@ -10096,7 +10096,7 @@
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@@ -10144,7 +10144,7 @@
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@@ -10193,7 +10193,7 @@
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@@ -10247,7 +10247,7 @@
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@@ -10301,7 +10301,7 @@
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@@ -10350,7 +10350,7 @@
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@@ -10404,7 +10404,7 @@
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@@ -10453,7 +10453,7 @@
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@@ -10507,7 +10507,7 @@
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@@ -10560,7 +10560,7 @@
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@@ -10613,7 +10613,7 @@
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@@ -10666,7 +10666,7 @@
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@@ -10715,7 +10715,7 @@
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@@ -10839,7 +10839,7 @@
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@@ -10888,7 +10888,7 @@
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@@ -10937,7 +10937,7 @@
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@@ -10986,7 +10986,7 @@
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@@ -11034,7 +11034,7 @@
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@@ -11082,7 +11082,7 @@
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@@ -11130,7 +11130,7 @@
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+          "version": "version:20"
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@@ -11178,7 +11178,7 @@
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+          "version": "version:20"
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@@ -11226,7 +11226,7 @@
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+          "version": "version:20"
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@@ -11274,7 +11274,7 @@
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+          "version": "version:20"
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@@ -11322,7 +11322,7 @@
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@@ -11370,7 +11370,7 @@
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+          "version": "version:20"
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@@ -11418,7 +11418,7 @@
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@@ -11466,7 +11466,7 @@
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+          "version": "version:20"
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@@ -11514,7 +11514,7 @@
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@@ -11562,7 +11562,7 @@
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@@ -11610,7 +11610,7 @@
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@@ -11658,7 +11658,7 @@
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@@ -11706,7 +11706,7 @@
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@@ -11754,7 +11754,7 @@
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@@ -11802,7 +11802,7 @@
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@@ -11850,7 +11850,7 @@
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@@ -11898,7 +11898,7 @@
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@@ -11946,7 +11946,7 @@
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@@ -11994,7 +11994,7 @@
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@@ -12042,7 +12042,7 @@
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+          "version": "version:20"
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@@ -12090,7 +12090,7 @@
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@@ -12138,7 +12138,7 @@
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+          "version": "version:20"
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@@ -12186,7 +12186,7 @@
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+          "version": "version:20"
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@@ -12234,7 +12234,7 @@
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+          "version": "version:20"
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@@ -12282,7 +12282,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12330,7 +12330,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12378,7 +12378,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12426,7 +12426,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12474,7 +12474,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12522,7 +12522,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12570,7 +12570,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12618,7 +12618,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12666,7 +12666,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12715,7 +12715,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12764,7 +12764,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12813,7 +12813,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12862,7 +12862,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12911,7 +12911,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
@@ -12960,7 +12960,7 @@
         {
           "name": "skia/bots/skimage",
           "path": "skimage",
-          "version": "version:19"
+          "version": "version:20"
         },
         {
           "name": "skia/bots/skp",
diff --git a/resources/invalid_images/invalid-offset.webp b/resources/invalid_images/invalid-offset.webp
new file mode 100644
index 0000000000..4a278d3467
--- /dev/null
+++ b/resources/invalid_images/invalid-offset.webp
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index dbc141ebd6..f0f2b21354 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -7,9 +7,10 @@
 
 #include "SkCodecPriv.h"
 #include "SkColorSpaceXform.h"
-#include "SkWebpCodec.h"
+#include "SkSampler.h"
 #include "SkStreamPriv.h"
 #include "SkTemplates.h"
+#include "SkWebpCodec.h"
 
 // A WebP decoder on top of (subset of) libwebp
 // For more information on WebP image format, and libwebp library, see:
@@ -59,6 +60,21 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
         return nullptr;
     }
 
+    const int width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
+    const int height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
+
+    // Sanity check for image size that's about to be decoded.
+    {
+        const int64_t size = sk_64_mul(width, height);
+        if (!sk_64_isS32(size)) {
+            return nullptr;
+        }
+        // now check that if we are 4-bytes per pixel, we also don't overflow
+        if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
+            return nullptr;
+        }
+    }
+
     WebPChunkIterator chunkIterator;
     SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
     sk_sp<SkColorSpace> colorSpace = nullptr;
@@ -73,36 +89,15 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
         colorSpace = SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named);
     }
 
-    // Since we do not yet support animation, we get the |width|, |height|, |color|, and |alpha|
-    // from the first frame.  It's the only frame we will decode.
-    //
-    // TODO:
-    // When we support animation, we'll want to report the canvas width and canvas height instead.
-    // We can get these from the |demux| directly.
-    // What |color| and |alpha| will we want to report though?  WebP allows different frames
-    // to be encoded in different ways, making the encoded format difficult to describe.
+    // Get the first frame and its "features" to determine the color and alpha types.
+    // Since we do not yet support animated webp, this is the only frame that we will
+    // decode.
     WebPIterator frame;
     SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
     if (!WebPDemuxGetFrame(demux, 1, &frame)) {
         return nullptr;
     }
 
-    // Sanity check for image size that's about to be decoded.
-    {
-        const int64_t size = sk_64_mul(frame.width, frame.height);
-        if (!sk_64_isS32(size)) {
-            return nullptr;
-        }
-        // now check that if we are 4-bytes per pixel, we also don't overflow
-        if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
-            return nullptr;
-        }
-    }
-
-    // TODO:
-    // The only reason we actually need to call WebPGetFeatures() is to get the |features.format|.
-    // This call actually re-reads the frame header.  Should we suggest that libwebp expose
-    // the format on the |frame|?
     WebPBitstreamFeatures features;
     VP8StatusCode status = WebPGetFeatures(frame.fragment.bytes, frame.fragment.size, &features);
     if (VP8_STATUS_OK != status) {
@@ -113,8 +108,8 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
     SkEncodedInfo::Alpha alpha;
     switch (features.format) {
         case 0:
-            // This indicates a "mixed" format.  We would see this for
-            // animated webps or for webps encoded in multiple fragments.
+            // This indicates a "mixed" format.  We could see this for
+            // animated webps (multiple fragments).
             // I believe that this is a rare case.
             // We could also guess kYUV here, but I think it makes more
             // sense to guess kBGRA which is likely closer to the final
@@ -125,7 +120,7 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
             break;
         case 1:
             // This is the lossy format (YUV).
-            if (SkToBool(features.has_alpha)) {
+            if (SkToBool(features.has_alpha) || frame.width != width || frame.height != height) {
                 color = SkEncodedInfo::kYUVA_Color;
                 alpha = SkEncodedInfo::kUnpremul_Alpha;
             } else {
@@ -143,9 +138,9 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
     }
 
     SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8);
-    SkWebpCodec* codecOut = new SkWebpCodec(features.width, features.height, info,
-                                            std::move(colorSpace), streamDeleter.release(),
-                                            demux.release(), std::move(data));
+    SkWebpCodec* codecOut = new SkWebpCodec(width, height, info, std::move(colorSpace),
+                                            streamDeleter.release(), demux.release(),
+                                            std::move(data));
     codecOut->setUnsupportedICC(unsupportedICC);
     return codecOut;
 }
@@ -217,48 +212,85 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
     // Free any memory associated with the buffer. Must be called last, so we declare it first.
     SkAutoTCallVProc<WebPDecBuffer, WebPFreeDecBuffer> autoFree(&(config.output));
 
-    SkIRect bounds = SkIRect::MakeSize(this->getInfo().dimensions());
+    WebPIterator frame;
+    SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
+    // If this succeeded in NewFromStream(), it should succeed again here.
+    SkAssertResult(WebPDemuxGetFrame(fDemux, 1, &frame));
+
+    // Get the frameRect.  libwebp will have already signaled an error if this is not fully
+    // contained by the canvas.
+    auto frameRect = SkIRect::MakeXYWH(frame.x_offset, frame.y_offset, frame.width, frame.height);
+    SkASSERT(this->getInfo().bounds().contains(frameRect));
+    bool frameIsSubset = frameRect.size() != this->getInfo().dimensions();
+    if (frameIsSubset) {
+        SkSampler::Fill(dstInfo, dst, rowBytes, 0, options.fZeroInitialized);
+    }
+
+    int dstX = frameRect.x();
+    int dstY = frameRect.y();
+    int subsetWidth = frameRect.width();
+    int subsetHeight = frameRect.height();
     if (options.fSubset) {
-        // Caller is requesting a subset.
-        if (!bounds.contains(*options.fSubset)) {
-            // The subset is out of bounds.
-            return kInvalidParameters;
+        SkIRect subset = *options.fSubset;
+        SkASSERT(this->getInfo().bounds().contains(subset));
+        SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
+        SkASSERT(this->getValidSubset(&subset) && subset == *options.fSubset);
+
+        if (!SkIRect::IntersectsNoEmptyCheck(subset, frameRect)) {
+            return kSuccess;
         }
 
-        bounds = *options.fSubset;
+        int minXOffset = SkTMin(dstX, subset.x());
+        int minYOffset = SkTMin(dstY, subset.y());
+        dstX -= minXOffset;
+        dstY -= minYOffset;
+        frameRect.offset(-minXOffset, -minYOffset);
+        subset.offset(-minXOffset, -minYOffset);
 
-        // This is tricky. libwebp snaps the top and left to even values. We could let libwebp
-        // do the snap, and return a subset which is a different one than requested. The problem
-        // with that approach is that the caller may try to stitch subsets together, and if we
-        // returned different subsets than requested, there would be artifacts at the boundaries.
-        // Instead, we report that we cannot support odd values for top and left..
-        if (!SkIsAlign2(bounds.fLeft) || !SkIsAlign2(bounds.fTop)) {
-            return kInvalidParameters;
-        }
+        // Just like we require that the requested subset x and y offset are even, libwebp
+        // guarantees that the frame x and y offset are even (it's actually impossible to specify
+        // an odd frame offset).  So we can still guarantee that the adjusted offsets are even.
+        SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
 
-#ifdef SK_DEBUG
-        {
-            // Make a copy, since getValidSubset can change its input.
-            SkIRect subset(bounds);
-            // That said, getValidSubset should *not* change its input, in this case; otherwise
-            // getValidSubset does not match the actual subsets we can do.
-            SkASSERT(this->getValidSubset(&subset) && subset == bounds);
-        }
-#endif
+        SkIRect intersection;
+        SkAssertResult(intersection.intersect(frameRect, subset));
+        subsetWidth = intersection.width();
+        subsetHeight = intersection.height();
 
         config.options.use_cropping = 1;
-        config.options.crop_left = bounds.fLeft;
-        config.options.crop_top = bounds.fTop;
-        config.options.crop_width = bounds.width();
-        config.options.crop_height = bounds.height();
+        config.options.crop_left = subset.x();
+        config.options.crop_top = subset.y();
+        config.options.crop_width = subsetWidth;
+        config.options.crop_height = subsetHeight;
     }
 
-    SkISize dstDimensions = dstInfo.dimensions();
-    if (bounds.size() != dstDimensions) {
-        // Caller is requesting scaling.
+    // Ignore the frame size and offset when determining if scaling is necessary.
+    int scaledWidth = subsetWidth;
+    int scaledHeight = subsetHeight;
+    SkISize srcSize = options.fSubset ? options.fSubset->size() : this->getInfo().dimensions();
+    if (srcSize != dstInfo.dimensions()) {
         config.options.use_scaling = 1;
-        config.options.scaled_width = dstDimensions.width();
-        config.options.scaled_height = dstDimensions.height();
+
+        if (frameIsSubset) {
+            float scaleX = ((float) dstInfo.width()) / srcSize.width();
+            float scaleY = ((float) dstInfo.height()) / srcSize.height();
+
+            // We need to be conservative here and floor rather than round.
+            // Otherwise, we may find ourselves decoding off the end of memory.
+            dstX = scaleX * dstX;
+            scaledWidth = scaleX * scaledWidth;
+            dstY = scaleY * dstY;
+            scaledHeight = scaleY * scaledHeight;
+            if (0 == scaledWidth || 0 == scaledHeight) {
+                return kSuccess;
+            }
+        } else {
+            scaledWidth = dstInfo.width();
+            scaledHeight = dstInfo.height();
+        }
+
+        config.options.scaled_width = scaledWidth;
+        config.options.scaled_height = scaledHeight;
     }
 
     // Swizzling between RGBA and BGRA is zero cost in a color transform.  So when we have a
@@ -274,21 +306,17 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
     // does not provide a row-by-row API.  This is a shame particularly in the F16 case,
     // where we need to allocate an extra image-sized buffer.
     SkAutoTMalloc<uint32_t> pixels;
-    if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
-        pixels.reset(dstDimensions.width() * dstDimensions.height());
-        config.output.u.RGBA.rgba = (uint8_t*) pixels.get();
-        config.output.u.RGBA.stride = (int) dstDimensions.width() * sizeof(uint32_t);
-        config.output.u.RGBA.size = config.output.u.RGBA.stride * dstDimensions.height();
-    } else {
-        config.output.u.RGBA.rgba = (uint8_t*) dst;
-        config.output.u.RGBA.stride = (int) rowBytes;
-        config.output.u.RGBA.size = dstInfo.getSafeSize(rowBytes);
-    }
-
-    WebPIterator frame;
-    SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
-    // If this succeeded in NewFromStream(), it should succeed again here.
-    SkAssertResult(WebPDemuxGetFrame(fDemux, 1, &frame));
+    bool isF16 = kRGBA_F16_SkColorType == dstInfo.colorType();
+    void* webpDst = isF16 ? pixels.reset(dstInfo.width() * dstInfo.height()) : dst;
+    size_t webpRowBytes = isF16 ? dstInfo.width() * sizeof(uint32_t) : rowBytes;
+    size_t totalBytes = isF16 ? webpRowBytes * dstInfo.height() : dstInfo.getSafeSize(webpRowBytes);
+    size_t dstBpp = SkColorTypeBytesPerPixel(dstInfo.colorType());
+    size_t webpBpp = isF16 ? sizeof(uint32_t) : dstBpp;
+
+    size_t offset = dstX * webpBpp + dstY * webpRowBytes;
+    config.output.u.RGBA.rgba = SkTAddOffset<uint8_t>(webpDst, offset);
+    config.output.u.RGBA.stride = (int) webpRowBytes;
+    config.output.u.RGBA.size = totalBytes - offset;
 
     SkAutoTCallVProc<WebPIDecoder, WebPIDelete> idec(WebPIDecode(nullptr, 0, &config));
     if (!idec) {
@@ -304,7 +332,8 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
             break;
         case VP8_STATUS_SUSPENDED:
             WebPIDecGetRGB(idec, rowsDecodedPtr, nullptr, nullptr, nullptr);
-            rowsDecoded = *rowsDecodedPtr;
+
+            rowsDecoded = dstY + *rowsDecodedPtr;
             result = kIncompleteInput;
             break;
         default:
@@ -316,14 +345,15 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
         SkAlphaType xformAlphaType = select_xform_alpha(dstInfo.alphaType(),
                                                         this->getInfo().alphaType());
 
-        uint32_t* src = (uint32_t*) config.output.u.RGBA.rgba;
+        uint32_t* xformSrc = (uint32_t*) config.output.u.RGBA.rgba;
+        void* xformDst = SkTAddOffset<void>(dst, dstBpp * dstX + rowBytes * dstY);
         size_t srcRowBytes = config.output.u.RGBA.stride;
-        for (int y = 0; y < rowsDecoded; y++) {
-            SkAssertResult(this->colorXform()->apply(dstColorFormat, dst,
-                    SkColorSpaceXform::kBGRA_8888_ColorFormat, src, dstInfo.width(),
+        for (int y = 0; y < rowsDecoded - dstY; y++) {
+            SkAssertResult(this->colorXform()->apply(dstColorFormat, xformDst,
+                    SkColorSpaceXform::kBGRA_8888_ColorFormat, xformSrc, scaledWidth,
                     xformAlphaType));
-            dst = SkTAddOffset<void>(dst, rowBytes);
-            src = SkTAddOffset<uint32_t>(src, srcRowBytes);
+            xformDst = SkTAddOffset<void>(xformDst, rowBytes);
+            xformSrc = SkTAddOffset<uint32_t>(xformSrc, srcRowBytes);
         }
     }
 
diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
index 4083cfa44b..8a4d6fc7ab 100644
--- a/tests/CodecTest.cpp
+++ b/tests/CodecTest.cpp
@@ -662,6 +662,8 @@ DEF_TEST(Codec_Empty, r) {
     test_invalid(r, "empty_images/zero-height.wbmp");
     // This image is an ico with an embedded mask-bmp.  This is illegal.
     test_invalid(r, "invalid_images/mask-bmp-ico.ico");
+    // It is illegal for a webp frame to not be fully contained by the canvas.
+    test_invalid(r, "invalid_images/invalid-offset.webp");
 #if defined(SK_CODEC_DECODES_RAW) && (!defined(_WIN32))
     test_invalid(r, "empty_images/zero_height.tiff");
 #endif