Do not attempt to scale webp.

Scaling webp ends triggers warnings on our valgrind bot. It also results in
generating many images in Skia Gold that look mostly the same except
for a few pixels along the right edge.

BUG=skia:4038

Review URL: https://codereview.chromium.org/1227843005

1 files changed, 5 insertions, 0 deletions

diff --git a/dm/DM.cpp b/dm/DM.cpp
index df16182072..dd072dcec6 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -212,6 +212,11 @@ static void push_codec_srcs(Path path) {
     const float scales[] = { 0.125f, 0.25f, 0.375f, 0.5f, 0.625f, 0.750f, 0.875f, 1.0f };
 
     for (float scale : scales) {
+        if (scale != 1.0f && (path.endsWith(".webp") || path.endsWith(".WEBP"))) {
+            // FIXME: skbug.com/4038 Scaling webp seems to leave some pixels uninitialized/
+            // compute their colors based on uninitialized values.
+            continue;
+        }
         // Build additional test cases for images that decode natively to non-canvas types
         switch(codec->getInfo().colorType()) {
             case kGray_8_SkColorType: