Fixing performance issue of creating imagebitmap from ImageData

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

Index: third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp b/third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp
index f01b7a7c7a05ab75ca9b3ab42603c815cefebff0..e38d85f0be71a481f8723dfa554457278ae03dd8 100644
--- a/third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp
+++ b/third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp
@@ -38,7 +38,7 @@
 
 namespace blink {
 
-UnacceleratedImageBufferSurface::UnacceleratedImageBufferSurface(const IntSize& size, OpacityMode opacityMode)
+UnacceleratedImageBufferSurface::UnacceleratedImageBufferSurface(const IntSize& size, OpacityMode opacityMode, ImageInitializationMode initializationMode)
     : ImageBufferSurface(size, opacityMode)
 {
     SkAlphaType alphaType = (Opaque == opacityMode) ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
@@ -46,8 +46,10 @@ UnacceleratedImageBufferSurface::UnacceleratedImageBufferSurface(const IntSize&
     SkSurfaceProps disableLCDProps(0, kUnknown_SkPixelGeometry);
     m_surface = adoptRef(SkSurface::NewRaster(info, Opaque == opacityMode ? 0 : &disableLCDProps));
 
-    if (m_surface)
-        clear();
+    if (initializationMode == DoNotInitializeImagePixels) {

[rickyz (no longer on Chrome), 2016/01/19 23:34:49]

Is this logic correct? Shouldn't this clear initializationMode ==
InitializeImagePixels?

On the other hand, ClusterFuzz said that this CL fixed the issue, so maybe I'm
just seeing things?

[rickyz (no longer on Chrome), 2016/01/19 23:43:10]

Never mind, I see that this was fixed in a later CL
(https://codereview.chromium.org/1407393002).

+        if (m_surface)
+            clear();
+    }
 }
 
 UnacceleratedImageBufferSurface::~UnacceleratedImageBufferSurface() { }