Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

cc/layer_tree_host_impl.h

 // Copyright 2011 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_LAYER_TREE_HOST_IMPL_H_
 #define CC_LAYER_TREE_HOST_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "cc/animation_events.h"
 #include "cc/cc_export.h"
 #include "cc/input_handler.h"
+#include "cc/layer_sorter.h"
 #include "cc/output_surface_client.h"
 #include "cc/render_pass.h"
 #include "cc/render_pass_sink.h"
 #include "cc/renderer.h"
 #include "cc/tile_manager.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/rect.h"
 
 namespace cc {
 
 class CompletionEvent;
 class DebugRectHistory;
 class FrameRateCounter;
 class LayerImpl;
 class LayerTreeHostImplTimeSourceAdapter;
 class LayerTreeImpl;
+class PinchZoomScrollbarsManager;
 class PageScaleAnimation;
 class RenderPassDrawQuad;
 class ResourceProvider;
 struct RendererCapabilities;
 struct RenderingStats;
 
 // LayerTreeHost->Proxy callback interface.
 class LayerTreeHostImplClient {
 public:
     virtual void didLoseOutputSurfaceOnImplThread() = 0;
@@ skipping 208 matching lines @@
     bool needsAnimateLayers() const { return m_needsAnimateLayers; }
     void setNeedsAnimateLayers() { m_needsAnimateLayers = true; }
 
     bool needsUpdateDrawProperties() const { return m_needsUpdateDrawProperties; }
     void setNeedsUpdateDrawProperties() { m_needsUpdateDrawProperties = true; }
 
     void setNeedsRedraw();
 
     void renderingStats(RenderingStats*) const;
 
-    void updateRootScrollLayerImplTransform();
+    void updateImplTransformOnRootChildren();
 
     void sendManagedMemoryStats(
        size_t memoryVisibleBytes,
        size_t memoryVisibleAndNearbyBytes,
        size_t memoryUseBytes);
 
     FrameRateCounter* fpsCounter() const { return m_fpsCounter.get(); }
     DebugRectHistory* debugRectHistory() const { return m_debugRectHistory.get(); }
     ResourceProvider* resourceProvider() const { return m_resourceProvider.get(); }
 
@@ skipping 79 matching lines @@
 
     void dumpRenderSurfaces(std::string*, int indent, const LayerImpl*) const;
 
     scoped_ptr<OutputSurface> m_outputSurface;
     scoped_ptr<ResourceProvider> m_resourceProvider;
     scoped_ptr<Renderer> m_renderer;
     scoped_ptr<TileManager> m_tileManager;
 
     scoped_ptr<LayerTreeImpl> m_activeTree;
 
+    scoped_ptr<LayerImpl> m_rootLayerImpl;
+    LayerImpl* m_rootScrollLayerImpl;
+    LayerImpl* m_currentlyScrollingLayerImpl;
+    int m_scrollingLayerIdFromPreviousTree;
     bool m_scrollDeltaIsInViewportSpace;
     LayerTreeSettings m_settings;
     LayerTreeDebugState m_debugState;
     gfx::Size m_layoutViewportSize;
     gfx::Size m_deviceViewportSize;
     float m_deviceScaleFactor;
     bool m_visible;
     bool m_contentsTexturesPurged;
     ManagedMemoryPolicy m_managedMemoryPolicy;
 
@@ skipping 30 matching lines @@
     size_t m_lastSentMemoryVisibleBytes;
     size_t m_lastSentMemoryVisibleAndNearbyBytes;
     size_t m_lastSentMemoryUseBytes;
 
     DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYER_TREE_HOST_IMPL_H_