Implement transform/clip support for Android WebView.

cc/trees/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_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 177 matching lines @@
   virtual void OnSwapBuffersComplete() OVERRIDE;
   virtual void SetFullRootLayerDamage() OVERRIDE;
   virtual void SetManagedMemoryPolicy(const ManagedMemoryPolicy& policy)
       OVERRIDE;
   virtual void EnforceManagedMemoryPolicy(const ManagedMemoryPolicy& policy)
       OVERRIDE;
   virtual bool HasImplThread() const OVERRIDE;
   virtual bool ShouldClearRootRenderPass() const OVERRIDE;
   virtual CompositorFrameMetadata MakeCompositorFrameMetadata() const OVERRIDE;
   virtual bool AllowPartialSwap() const OVERRIDE;
+  virtual gfx::Vector2d DeviceViewportOffset() const OVERRIDE;

[enne (OOO), 2013/05/29 20:34:12]

Unless I'm misunderstanding your requirements, it sounds like there are two
things you need from the output surface: a transform and a device viewport rect.
 However, I see viewport size, viewport offset, device clip, and device
transform.

Does it make sense to merge the viewport offset and size into just a rect? It
looks like that gets used in a number of places as a rect.

Also, is there a difference between viewport rect and device clip? Can these be
merged?

 
   // TileManagerClient implementation.
   virtual void ScheduleManageTiles() OVERRIDE;
   virtual void DidInitializeVisibleTile() OVERRIDE;
   virtual bool ShouldForceTileUploadsRequiredForActivationToComplete() const
       OVERRIDE;
 
   // OutputSurfaceClient implementation.
+  virtual void SetDeviceTransformAndClip(const gfx::Transform& transform,
+                                         gfx::Rect clip) OVERRIDE;
   virtual void SetNeedsRedrawRect(gfx::Rect rect) OVERRIDE;
   virtual void OnVSyncParametersChanged(base::TimeTicks timebase,
                                         base::TimeDelta interval) OVERRIDE;
   virtual void BeginFrame(base::TimeTicks frame_time)
       OVERRIDE;
   virtual void OnSendFrameToParentCompositorAck(const CompositorFrameAck& ack)
       OVERRIDE;
 
   // Called from LayerTreeImpl.
   void OnCanDrawStateChangedForTree();
@@ skipping 47 matching lines @@
 
   void SetViewportSize(gfx::Size device_viewport_size);
   gfx::Size device_viewport_size() const { return device_viewport_size_; }
 
   void SetOverdrawBottomHeight(float overdraw_bottom_height);
   float overdraw_bottom_height() const { return overdraw_bottom_height_; }
 
   void SetDeviceScaleFactor(float device_scale_factor);
   float device_scale_factor() const { return device_scale_factor_; }
 
+  gfx::Rect DeviceClip() const;
+  gfx::Transform DeviceTransform() const;
+
   scoped_ptr<ScrollAndScaleSet> ProcessScrollDeltas();
 
   bool needs_animate_layers() const {
     return !animation_registrar_->active_animation_controllers().empty();
   }
 
   void SendManagedMemoryStats(
       size_t memory_visible_bytes,
       size_t memory_visible_and_nearby_bytes,
       size_t memory_use_bytes);
@@ skipping 208 matching lines @@
 
   // The maximum memory that would be used by the prioritized resource
   // manager, if there were no limit on memory usage.
   size_t max_memory_needed_bytes_;
 
   size_t last_sent_memory_visible_bytes_;
   size_t last_sent_memory_visible_and_nearby_bytes_;
   size_t last_sent_memory_use_bytes_;
 
   gfx::Rect viewport_damage_rect_;
+  gfx::Rect device_clip_;
+  gfx::Transform device_transform_;
 
   base::TimeTicks current_frame_timeticks_;
   base::Time current_frame_time_;
 
   scoped_ptr<AnimationRegistrar> animation_registrar_;
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_