Fix paint invalidation and painting for composited-scrolling input elements.

third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ObjectPaintInvalidator_h
 #define ObjectPaintInvalidator_h
 
 #include "core/CoreExport.h"
 #include "platform/graphics/PaintInvalidationReason.h"
 #include "wtf/Allocator.h"
@@ skipping 32 matching lines @@
 
     // The caller should ensure the painting layer has been setNeedsRepaint before calling this function.
     void invalidateDisplayItemClient(const DisplayItemClient&, PaintInvalidationReason);
 
     // Actually do the paint invalidate of rect r for this object which has been computed in the coordinate space
     // of the GraphicsLayer backing of |paintInvalidationContainer|. Note that this coordinaten space is not the same
     // as the local coordinate space of |paintInvalidationContainer| in the presence of layer squashing.
     void invalidatePaintUsingContainer(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason);
 
     // Invalidate the paint of a specific subrectangle within a given object. The rect is in the object's coordinate space.
-    void invalidatePaintRectangle(const LayoutRect&);
+    // If a DisplayItemClient is specified, that client is invalidated rather than |m_object|.
+    void invalidatePaintRectangle(const LayoutRect&, DisplayItemClient*);
 
     void invalidatePaintIncludingNonCompositingDescendants();
     void invalidatePaintIncludingNonSelfPaintingLayerDescendants(const LayoutBoxModelObject& paintInvalidationContainer);
 
 private:
     void invalidatePaintIncludingNonSelfPaintingLayerDescendantsInternal(const LayoutBoxModelObject& paintInvalidationContainer);
     void setBackingNeedsPaintInvalidationInRect(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason);
 
 protected:
     const LayoutObject& m_object;
@@ skipping 33 matching lines @@
     WTF_MAKE_NONCOPYABLE(DisablePaintInvalidationStateAsserts);
 public:
     DisablePaintInvalidationStateAsserts();
 private:
     AutoReset<bool> m_disabler;
 };
 
 } // namespace blink
 
 #endif