Avoid integer overflow in SkIcoCodec

Definitely good to avoid overflow here.

FWIW, this looks to be harmless for Android's current use.
They will just fail later on when trying to allocate the
bitmap.

BUG=skia:5857

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3527

Change-Id: Ia1fb7d864d21ecdb127a1dd1a72cab8375cb43fb
Reviewed-on: https://skia-review.googlesource.com/3527
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/codec/SkIcoCodec.cpp b/src/codec/SkIcoCodec.cpp
index 63b72c4039..d01904dc1b 100644
--- a/src/codec/SkIcoCodec.cpp
+++ b/src/codec/SkIcoCodec.cpp
@@ -157,11 +157,12 @@ SkCodec* SkIcoCodec::NewFromStream(SkStream* stream) {
     }
 
     // Use the largest codec as a "suggestion" for image info
-    uint32_t maxSize = 0;
-    uint32_t maxIndex = 0;
-    for (int32_t i = 0; i < codecs->count(); i++) {
+    size_t maxSize = 0;
+    int maxIndex = 0;
+    for (int i = 0; i < codecs->count(); i++) {
         SkImageInfo info = codecs->operator[](i)->getInfo();
-        uint32_t size = info.width() * info.height();
+        size_t size = info.getSafeSize(info.minRowBytes());
+
         if (size > maxSize) {
             maxSize = size;
             maxIndex = i;