Save a bitmap copy when advancing to dependent GIF and WebP animation frames

third_party/WebKit/Source/core/frame/ImageBitmap.cpp

Index: third_party/WebKit/Source/core/frame/ImageBitmap.cpp
diff --git a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
index 990fd97df9293e470145e6e37e5d0c9368ae8726..c87e3eb627e6bc5ac6d4830b2a9ca93db0cce713 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
@@ -42,12 +42,6 @@ static inline IntRect normalizeRect(const IntRect& rect)
         std::max(rect.height(), -rect.height()));
 }
 
-static bool frameIsValid(const SkBitmap& frameBitmap)
-{
-    ASSERT(!frameBitmap.isNull() && !frameBitmap.empty() && frameBitmap.isImmutable());
-    return frameBitmap.colorType() == kN32_SkColorType;
-}
-
 ParsedOptions parseOptions(const ImageBitmapOptions& options, Optional<IntRect> cropRect, IntSize sourceSize)
 {
     ParsedOptions parsedOptions;
@@ -180,10 +174,8 @@ PassRefPtr<SkImage> ImageBitmap::getSkImageFromDecoder(std::unique_ptr<ImageDeco
     ImageFrame* frame = decoder->frameBufferAtIndex(0);
     if (!frame || frame->getStatus() != ImageFrame::FrameComplete)
         return nullptr;
-    SkBitmap bitmap = frame->bitmap();
-    if (!frameIsValid(bitmap))
-        return nullptr;
-    return fromSkSp(SkImage::MakeFromBitmap(bitmap));
+    DCHECK_EQ(frame->bitmap().colorType(), kN32_SkColorType);

[Peter Kasting, 2016/08/30 06:59:40]

The old code handled this conditionally, so this is a behavior change.  Is this
safe?

Nit: (expected, actual)

[aleksandar.stojiljkovic, 2016/09/21 20:56:57]

Done. Didn't see how it could be different from kN32 but agree - no need to
introduce behavior change.

+    return frame->finalizePixelsAndGetImage();
 }
 
 bool ImageBitmap::isResizeOptionValid(const ImageBitmapOptions& options, ExceptionState& exceptionState)