Eliminate copies of encoded image data

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

Index: third_party/WebKit/Source/platform/graphics/PictureSnapshot.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/PictureSnapshot.cpp b/third_party/WebKit/Source/platform/graphics/PictureSnapshot.cpp
index 7d322be9caf0a951dca06ff01ad53ab621f3833f..2264648c8a3f0f4a60ed7faa9139d86058c1775e 100644
--- a/third_party/WebKit/Source/platform/graphics/PictureSnapshot.cpp
+++ b/third_party/WebKit/Source/platform/graphics/PictureSnapshot.cpp
@@ -38,7 +38,9 @@
 #include "platform/graphics/skia/ImagePixelLocker.h"
 #include "platform/image-decoders/ImageDecoder.h"
 #include "platform/image-decoders/ImageFrame.h"
+#include "platform/image-decoders/SegmentReader.h"
 #include "platform/image-encoders/skia/PNGImageEncoder.h"
+#include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/core/SkStream.h"
@@ -56,11 +58,14 @@ PictureSnapshot::PictureSnapshot(PassRefPtr<const SkPicture> picture)
 
 static bool decodeBitmap(const void* data, size_t length, SkBitmap* result)
 {
-    RefPtr<SharedBuffer> buffer = SharedBuffer::create(static_cast<const char*>(data), length);
-    OwnPtr<ImageDecoder> imageDecoder = ImageDecoder::create(*buffer, ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileIgnored);
+    OwnPtr<ImageDecoder> imageDecoder = ImageDecoder::create(static_cast<const char*>(data), length,
+        ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileIgnored);
     if (!imageDecoder)
         return false;
-    imageDecoder->setData(buffer.get(), true);
+
+    // No need to copy the data; this decodes immediately.
+    RefPtr<SegmentReader> segmentReader = SegmentReader::createFromSkData(adoptRef(SkData::NewWithoutCopy(data, length)));
+    imageDecoder->setData(segmentReader.release(), true);
     ImageFrame* frame = imageDecoder->frameBufferAtIndex(0);
     if (!frame)
         return true;