Decode GIF image frames on demand.

Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp

Index: Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp
diff --git a/Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp b/Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp
index d681e830b1b41b5b2c15a4ff818fec4f57e5263e..a63bcf771d7be892779b2499a3c884a599cd796d 100644
--- a/Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp
+++ b/Source/core/platform/graphics/chromium/DeferredImageDecoder.cpp
@@ -172,12 +172,12 @@ int DeferredImageDecoder::repetitionCount() const
     return m_actualDecoder ? m_actualDecoder->repetitionCount() : cAnimationNone;
 }
 
-void DeferredImageDecoder::clearFrameBufferCache(size_t clearBeforeFrame)
+void DeferredImageDecoder::clearFrameBufferCache(size_t clearExceptFrame)
 {
     // If image decoding is deferred then frame buffer cache is managed by
     // the compositor and this call is ignored.
     if (m_actualDecoder)
-        m_actualDecoder->clearFrameBufferCache(clearBeforeFrame);
+        m_actualDecoder->clearFrameBufferCache(clearExceptFrame);
 }
 
 bool DeferredImageDecoder::frameHasAlphaAtIndex(size_t index) const