High CPU and increased memory usage fix for high-res (GIF, WEBP...) animations.

third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp

Index: third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp b/third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp
index f1d76fd87415897d55de43781599b662de78c1d1..0be98893f44c0a6b9dcd9c665a1fa68c5df2a479 100644
--- a/third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp
@@ -27,7 +27,6 @@
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/DecodingImageGenerator.h"
-#include "platform/graphics/FrameData.h"
 #include "platform/graphics/ImageDecodingStore.h"
 #include "platform/graphics/ImageFrameGenerator.h"
 #include "third_party/skia/include/core/SkImage.h"
@@ -35,6 +34,23 @@
 
 namespace blink {
 
+struct DeferredFrameData {

[Peter Kasting, 2016/04/28 23:07:55]

This probably needs comments about why you can't use FrameData (maybe leaving
some fields uninitialized?) and how you selected which fields to preserve.

Furthermore, it seems like FrameData is pretty much only used by BitmapImage
after this change, in which case I'd consider moving it to BitmapImage.cpp.

[aleksandar.stojiljkovic, 2016/04/29 17:17:43]

After second patch these two diverged further -  DeferredFrameData got uniqueID
and FrameData has 2 flag fields that DeferredFrameData doesn't need.
Didn't move FrameData to BitmapFrame.cpp as it is used from BitmapImageTest.cpp
too. 

+    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
+    WTF_MAKE_NONCOPYABLE(DeferredFrameData);
+public:
+    DeferredFrameData()
+        : m_orientation(DefaultImageOrientation)
+        , m_duration(0)
+        , m_isComplete(false)
+        , m_frameBytes(0)
+    {}
+
+    ImageOrientation m_orientation;
+    float m_duration;
+    bool m_isComplete : 1;
+    size_t m_frameBytes;
+};
+
 bool DeferredImageDecoder::s_enabled = true;
 
 PassOwnPtr<DeferredImageDecoder> DeferredImageDecoder::create(const SharedBuffer& data, ImageDecoder::AlphaOption alphaOption, ImageDecoder::GammaAndColorProfileOption colorOptions)
@@ -89,16 +105,15 @@ PassRefPtr<SkImage> DeferredImageDecoder::createFrameAtIndex(size_t index)
     prepareLazyDecodedFrames();
 
     if (index < m_frameData.size()) {
-        FrameData* frameData = &m_frameData[index];
-        // ImageFrameGenerator has the latest known alpha state. There will be a
-        // performance boost if this frame is opaque.
-        ASSERT(m_frameGenerator);
-        frameData->m_hasAlpha = m_frameGenerator->hasAlpha(index);
+        DeferredFrameData* frameData = &m_frameData[index];
         if (m_actualDecoder)
             frameData->m_frameBytes = m_actualDecoder->frameBytesAtIndex(index);
         else
             frameData->m_frameBytes = m_size.area() * sizeof(ImageFrame::PixelData);
-        return createFrameImageAtIndex(index, !frameData->m_hasAlpha);
+        // ImageFrameGenerator has the latest known alpha state. There will be a
+        // performance boost if this frame is opaque.
+        ASSERT(m_frameGenerator);
+        return createFrameImageAtIndex(index, !m_frameGenerator->hasAlpha(index));
     }
 
     if (!m_actualDecoder || m_actualDecoder->failed())
@@ -251,7 +266,6 @@ void DeferredImageDecoder::prepareLazyDecodedFrames()
         return;
 
     for (size_t i = previousSize; i < m_frameData.size(); ++i) {
-        m_frameData[i].m_haveMetadata = true;
         m_frameData[i].m_duration = m_actualDecoder->frameDurationAtIndex(i);
         m_frameData[i].m_orientation = m_actualDecoder->orientation();
         m_frameData[i].m_isComplete = m_actualDecoder->frameIsCompleteAtIndex(i);
@@ -300,3 +314,10 @@ bool DeferredImageDecoder::hotSpot(IntPoint& hotSpot) const
 }
 
 } // namespace blink
+
+namespace WTF {
+template<> struct VectorTraits<blink::DeferredFrameData> : public SimpleClassVectorTraits<blink::DeferredFrameData> {
+    STATIC_ONLY(VectorTraits);
+    static const bool canInitializeWithMemset = false; // Not all DeferredFrameData members initialize to 0.
+};
+}