Use enclosingIntRect instead of pixelSnappedIntRect to expand invalidation.

Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 398 matching lines @@
     ASSERT(!paintInvalidationRect.isEmpty());
 
     if (document().printing() || !m_frameView)
         return;
 
     ASSERT(layer()->compositingState() == PaintsIntoOwnBacking || !frame()->ownerLayoutObject());
 
     if (layer()->compositingState() == PaintsIntoOwnBacking) {
         setBackingNeedsPaintInvalidationInRect(paintInvalidationRect, invalidationReason);
     } else {
-        m_frameView->contentRectangleForPaintInvalidation(pixelSnappedIntRect(paintInvalidationRect));
+        m_frameView->contentRectangleForPaintInvalidation(enclosingIntRect(paintInvalidationRect));
     }
 }
 
 void LayoutView::invalidatePaintForViewAndCompositedLayers()
 {
     setShouldDoFullPaintInvalidation();
 
     // The only way we know how to hit these ASSERTS below this point is via the Chromium OS login screen.
     DisableCompositingQueryAsserts disabler;
 
@@ skipping 576 matching lines @@
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 void LayoutView::willBeDestroyed()
 {
     LayoutBlockFlow::willBeDestroyed();
     m_compositor.clear();
 }
 
 } // namespace blink