Generalize browser controls adjustment for arbitrary scrollers.

third_party/WebKit/Source/core/frame/VisualViewport.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 569 matching lines @@
   IntSize clamped = toIntSize(offset);
   clamped = clamped.shrunkTo(max);
   clamped = clamped.expandedTo(min);
   return IntPoint(clamped);
 }
 
 void VisualViewport::setBrowserControlsAdjustment(float adjustment) {
   m_browserControlsAdjustment = adjustment;
 }
 
+float VisualViewport::browserControlsAdjustment() const {
+  return m_browserControlsAdjustment;
+}
+
 IntRect VisualViewport::scrollableAreaBoundingBox() const {
   // This method should return the bounding box in the parent view's coordinate
   // space; however, VisualViewport technically isn't a child of any Frames.
   // Nonetheless, the VisualViewport always occupies the entire main frame so
   // just return that.
   LocalFrame* frame = mainFrame();
 
   if (!frame || !frame->view())
     return IntRect();
 
   return frame->view()->frameRect();
 }
 
 IntSize VisualViewport::contentsSize() const {
   LocalFrame* frame = mainFrame();
 
   if (!frame || !frame->view())
     return IntSize();
 
+  // TODO(bokan): This should be the layout viewport rather than main FrameView.
   return frame->view()->visibleContentRect(IncludeScrollbars).size();
 }
 
 IntRect VisualViewport::visibleContentRect(
     IncludeScrollbarsInRect scrollbarInclusion) const {
   // TODO(ymalik): We're losing precision here and below. visibleRect should
   // be replaced with visibleContentRect.
   IntRect rect = IntRect(visibleRect());
   if (scrollbarInclusion == ExcludeScrollbars) {
     RootFrameViewport* rootFrameViewport =
@@ skipping 217 matching lines @@
   } else if (graphicsLayer == m_rootTransformLayer.get()) {
     name = "Root Transform Layer";
   } else {
     ASSERT_NOT_REACHED();
   }
 
   return name;
 }
 
 }  // namespace blink