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

content/renderer/gpu/render_widget_compositor.h

 // Copyright (c) 2013 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 CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 #define CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ skipping 32 matching lines @@
 
   virtual ~RenderWidgetCompositor();
 
   const base::WeakPtr<cc::InputHandler>& GetInputHandler();
   bool BeginMainFrameRequested() const;
   void SetNeedsDisplayOnAllLayers();
   void SetRasterizeOnlyVisibleContent();
   void UpdateTopControlsState(cc::TopControlsState constraints,
                               cc::TopControlsState current,
                               bool animate);
-  void SetTopControlsLayoutHeight(float top_controls_layout_height);
   void SetNeedsRedrawRect(gfx::Rect damage_rect);
   // Like setNeedsRedraw but forces the frame to be drawn, without early-outs.
   // Redraw will be forced after the next commit
   void SetNeedsForcedRedraw();
   // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped
   // LatencyInfoSwapPromiseMonitor. During the life time of the
   // LatencyInfoSwapPromiseMonitor, if SetNeedsCommit() or SetNeedsUpdateLayer()
   // is called on LayerTreeHost, the original latency info will be turned
   // into a LatencyInfoSwapPromise.
   scoped_ptr<cc::SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
@@ skipping 52 matching lines @@
       const blink::WebLayer* outerViewportScrollLayer) OVERRIDE;
   virtual void clearViewportLayers() OVERRIDE;
   virtual void registerSelection(const blink::WebSelectionBound& start,
                                  const blink::WebSelectionBound& end) OVERRIDE;
   virtual void clearSelection() OVERRIDE;
   virtual void setShowFPSCounter(bool show);
   virtual void setShowPaintRects(bool show);
   virtual void setShowDebugBorders(bool show);
   virtual void setContinuousPaintingEnabled(bool enabled);
   virtual void setShowScrollBottleneckRects(bool show);
+  virtual void setTopControlsContentOffset(int);

[bokan, 2014/08/28 18:42:45]

It feels strange that this class ends up with two of the same named methods
(with case diff) but they come from separate interfaces where it makes sense in
those contexts. WDYT?

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

Could you instead add an additional parameter to applyScrollAndScale and rename
that to something else (applyImplThreadDeltas?).  Aside from this issue, I find
bundling related state into the same method can help avoid clamping-related bugs
(avoids problems like you first make the viewport smaller, scroll clamped, then
you adjust the scroll...)

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

I had a FIXME to do just that. My concern was that the inner/outer viewport
scroll offsets are set before applyScrollAndScale and so I was worried about
clamping and I was a bit hesitant to change around the order these things happen
in for this CL. I do feel like I understand these paths better now so I'll take
another look here.

[bokan, 2014/09/02 18:57:16]

Done.

 
   // cc::LayerTreeHostClient implementation.
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE;
   virtual void DidBeginMainFrame() OVERRIDE;
   virtual void BeginMainFrame(const cc::BeginFrameArgs& args) OVERRIDE;
   virtual void Layout() OVERRIDE;
   virtual void ApplyScrollAndScale(const gfx::Vector2d& scroll_delta,
                                    float page_scale) OVERRIDE;
+  virtual void SetTopControlsContentOffset(int offset) OVERRIDE;
   virtual scoped_ptr<cc::OutputSurface> CreateOutputSurface(bool fallback)
       OVERRIDE;
   virtual void DidInitializeOutputSurface() OVERRIDE;
   virtual void WillCommit() OVERRIDE;
   virtual void DidCommit() OVERRIDE;
   virtual void DidCommitAndDrawFrame() OVERRIDE;
   virtual void DidCompleteSwapBuffers() OVERRIDE;
   virtual void RateLimitSharedMainThreadContext() OVERRIDE;
 
   // cc::LayerTreeHostSingleThreadClient implementation.
   virtual void ScheduleAnimation() OVERRIDE;
   virtual void DidPostSwapBuffers() OVERRIDE;
   virtual void DidAbortSwapBuffers() OVERRIDE;
 
  private:
   RenderWidgetCompositor(RenderWidget* widget, bool threaded);
 
   void Initialize(cc::LayerTreeSettings settings);
 
   bool threaded_;
   RenderWidget* widget_;
   scoped_ptr<cc::LayerTreeHost> layer_tree_host_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_