Made Blink aware of top controls offset (Chromium-side)

cc/trees/layer_tree_host_client.h

 // Copyright 2012 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 CC_TREES_LAYER_TREE_HOST_CLIENT_H_
 #define CC_TREES_LAYER_TREE_HOST_CLIENT_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
@@ skipping 11 matching lines @@
 class LayerTreeHostClient {
  public:
   virtual void WillBeginMainFrame(int frame_id) = 0;
   // Marks finishing compositing-related tasks on the main thread. In threaded
   // mode, this corresponds to DidCommit().
   virtual void BeginMainFrame(const BeginFrameArgs& args) = 0;
   virtual void DidBeginMainFrame() = 0;
   virtual void Layout() = 0;
   virtual void ApplyScrollAndScale(const gfx::Vector2d& scroll_delta,
                                    float page_scale) = 0;
+  // TODO(bokan): This method is a shim while we need to keep both
+  // virtual-viewport and ordinary pinch modes around. It will be removed in
+  // place of the above method once we remove old-style pinch.
+  virtual void SetTopControlsContentOffset(int offset) = 0;

[aelias_OOO_until_Jul13, 2014/08/29 04:37:01]

I think if you stop baking this value into FrameView size (mentioned below how
we can avoid it) we can use floats everywhere instead of ints.

[bokan, 2014/08/29 18:02:14]

Assuming this can be done impl-side then yes. See my concerns about that in
comment in render_widget.

   // Creates an OutputSurface. If fallback is true, it should attempt to
   // create an OutputSurface that is guaranteed to initialize correctly.
   virtual scoped_ptr<OutputSurface> CreateOutputSurface(bool fallback) = 0;
   virtual void DidInitializeOutputSurface() = 0;
   virtual void WillCommit() = 0;
   virtual void DidCommit() = 0;
   virtual void DidCommitAndDrawFrame() = 0;
   virtual void DidCompleteSwapBuffers() = 0;
 
   // Requests that the client insert a rate limiting token in the shared main
   // thread context's command stream that will block if the context gets too far
   // ahead of the compositor's command stream. Only needed if the tree contains
   // a TextureLayer that calls SetRateLimitContext(true).
   virtual void RateLimitSharedMainThreadContext() {}
 
   // This hook is for testing.
   virtual void DidFailToInitializeOutputSurface() {}
 
  protected:
   virtual ~LayerTreeHostClient() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_CLIENT_H_