Don't let PaintInvalidationLocationChange shadow other reasons

third_party/WebKit/Source/core/layout/LayoutBoxModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google 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
@@ skipping 376 matching lines @@
 
 void LayoutBoxModelObject::invalidateTreeIfNeeded(const PaintInvalidationState& paintInvalidationState)
 {
     ASSERT(!needsLayout());
 
     PaintInvalidationState newPaintInvalidationState(paintInvalidationState, *this);
     if (!shouldCheckForPaintInvalidation(newPaintInvalidationState))
         return;
 
     LayoutRect previousPaintInvalidationRect = this->previousPaintInvalidationRect();
+    LayoutPoint previousPosition = previousPositionFromPaintInvalidationBacking();
     PaintInvalidationReason reason = invalidatePaintIfNeeded(newPaintInvalidationState);
     clearPaintInvalidationFlags(newPaintInvalidationState);
 
     if (reason == PaintInvalidationDelayedFull)
         paintInvalidationState.pushDelayedPaintInvalidationTarget(*this);
 
-    if (reason == PaintInvalidationLocationChange)
+    if (previousPosition != previousPositionFromPaintInvalidationBacking())
         newPaintInvalidationState.setForceSubtreeInvalidationWithinContainer();
 
     // TODO(wangxianzhu): Combine this function into LayoutObject::invalidateTreeIfNeeded() when removing the following workarounds.
 
     // TODO(wangxianzhu): This is a workaround for crbug.com/533277. Will remove when we enable paint offset caching.
     if (reason != PaintInvalidationNone && hasPercentageTransform(styleRef()))
         newPaintInvalidationState.setForceSubtreeInvalidationWithinContainer();
 
     // TODO(wangxianzhu): This is a workaround for crbug.com/490725. We don't have enough saved information to do accurate check
     // of clipping change. Will remove when we remove rect-based paint invalidation.
@@ skipping 719 matching lines @@
     if (rootElementStyle->hasBackground())
         return false;
 
     if (node() != document().firstBodyElement())
         return false;
 
     return true;
 }
 
 } // namespace blink