Don't convert invalidations to a FloatRect.

Source/platform/graphics/Canvas2DLayerBridge.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 548 matching lines @@
 {
     ASSERT(!m_destructionInProgress);
     ASSERT(m_layer);
     return m_layer->layer();
 }
 
 void Canvas2DLayerBridge::finalizeFrame(const FloatRect &dirtyRect)
 {
     ASSERT(!m_destructionInProgress);
     Canvas2DLayerManager::get().layerDidDraw(this);
-    m_layer->layer()->invalidateRect(dirtyRect);
+    m_layer->layer()->invalidateRect(enclosingIntRect(dirtyRect));
     m_didRecordDrawCommand = true;
 }
 
 Platform3DObject Canvas2DLayerBridge::getBackingTexture()
 {
     ASSERT(!m_destructionInProgress);
     if (!checkSurfaceValid())
         return 0;
     m_canvas->flush();
     context()->flush();
@@ skipping 13 matching lines @@
     // This copy constructor should only be used for Vector reallocation
     // Assuming 'other' is to be destroyed, we transfer m_image and
     // m_parentLayerBridge ownership rather than do a refcount dance.
     memcpy(&m_mailbox, &other.m_mailbox, sizeof(m_mailbox));
     m_image = const_cast<MailboxInfo*>(&other)->m_image.release();
     m_parentLayerBridge = const_cast<MailboxInfo*>(&other)->m_parentLayerBridge.release();
     m_status = other.m_status;
 }
 
 } // namespace blink