Rework View Layer Draw() to use the Layer::DrawTree() method and the LayerDelegate.

ui/gfx/compositor/layer.h

 // Copyright (c) 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 UI_GFX_COMPOSITOR_LAYER_H_
 #define UI_GFX_COMPOSITOR_LAYER_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 42 matching lines @@
   bool Contains(const Layer* other) const;
 
   // The transform, relative to the parent.
   void SetTransform(const ui::Transform& transform);
   const ui::Transform& transform() const { return transform_; }
 
   // The bounds, relative to the parent.
   void SetBounds(const gfx::Rect& bounds);
   const gfx::Rect& bounds() const { return bounds_; }
 
+  // Sets |visible_|. The Layer is drawn by Draw() only when visible_ is true.
+  bool visible() const { return visible_; }
+  void set_visible(bool visible) { visible_ = visible; }
+
   // Converts a point from the coordinates of |source| to the coordinates of
   // |target|. Necessarily, |source| and |target| must inhabit the same Layer
   // tree.
   static void ConvertPointToLayer(const Layer* source,
                                   const Layer* target,
                                   gfx::Point* point);
 
   // See description in View for details
   void SetFillsBoundsOpaquely(bool fills_bounds_opaquely);
   bool fills_bounds_opaquely() const { return fills_bounds_opaquely_; }
 
   const gfx::Rect& hole_rect() const {  return hole_rect_; }
 
   // The compositor.
   const Compositor* compositor() const { return compositor_; }
   Compositor* compositor() { return compositor_; }
 
   // Passing NULL will cause the layer to get a texture from its compositor.
   void SetTexture(ui::Texture* texture);
   const ui::Texture* texture() const { return texture_.get(); }
 
   // Resets the canvas of the texture.
   void SetCanvas(const SkCanvas& canvas, const gfx::Point& origin);
 
   // Adds |invalid_rect| to the Layer's pending invalid rect, and schedules a
   // repaint if the Layer has an associated LayerDelegate that can handle the
   // repaint.
   void SchedulePaint(const gfx::Rect& invalid_rect);
 
-// Draws the layer with hole if hole is non empty.
-// hole looks like:
-//
-//  layer____________________________
-//  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
-//  |xxxxxxxxxxxxx top xxxxxxxxxxxxxx|
-//  |________________________________|
-//  |xxxxx|                    |xxxxx|
-//  |xxxxx|      Hole Rect     |xxxxx|
-//  |left | (not composited)   |right|
-//  |_____|____________________|_____|
-//  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
-//  |xxxxxxxxxx bottom xxxxxxxxxxxxxx|
-//  |________________________________|
-//
-// Legend:
-//   composited area: x
+  // Draws the layer with hole if hole is non empty.
+  // hole looks like:
+  //
+  //  layer____________________________
+  //  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
+  //  |xxxxxxxxxxxxx top xxxxxxxxxxxxxx|
+  //  |________________________________|
+  //  |xxxxx|                    |xxxxx|
+  //  |xxxxx|      Hole Rect     |xxxxx|
+  //  |left | (not composited)   |right|
+  //  |_____|____________________|_____|
+  //  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
+  //  |xxxxxxxxxx bottom xxxxxxxxxxxxxx|
+  //  |________________________________|
+  //
+  // Legend:
+  //   composited area: x
   void Draw();
 
+  // Draws a tree of Layers, by calling Draw() on each in the hierarchy starting
+  // with the receiver.
+  void DrawTree();
+
  private:
   // calls Texture::Draw only if the region to be drawn is non empty
   void DrawRegion(const ui::TextureDrawParams& params,
                   const gfx::Rect& region_to_draw);
 
   // Called during the Draw() pass to freshen the Layer's contents from the
   // delegate.
   void UpdateLayerCanvas();
 
   // A hole in a layer is an area in the layer that does not get drawn
@@ skipping 16 matching lines @@
   scoped_refptr<ui::Texture> texture_;
 
   Layer* parent_;
 
   std::vector<Layer*> children_;
 
   ui::Transform transform_;
 
   gfx::Rect bounds_;
 
+  bool visible_;
+
   bool fills_bounds_opaquely_;
 
   gfx::Rect hole_rect_;
 
   gfx::Rect invalid_rect_;
 
   LayerDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_GFX_COMPOSITOR_LAYER_H_