Implement initial version of scroll end effect

chrome/browser/ui/views/frame/scroll_end_effect_controller_ash.h

 // Copyright 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 CHROME_BROWSER_UI_VIEWS_FRAME_SCROLL_END_EFFECT_CONTROLLER_ASH_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_SCROLL_END_EFFECT_CONTROLLER_ASH_H_
 
 #include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/ui/views/frame/scroll_end_effect_controller.h"
+#include "ui/compositor/layer.h"
+#include "ui/gfx/rect.h"
+
+namespace views {
+class View;
+}
 
 class ScrollEndEffectControllerAsh : public ScrollEndEffectController {
  public:
-  ScrollEndEffectControllerAsh();
+  explicit ScrollEndEffectControllerAsh(BrowserView* view);
   virtual ~ScrollEndEffectControllerAsh();
 
   // ScrollEndEffectController overides:
   virtual void OverscrollUpdate(int delta_y) OVERRIDE;
 
  private:
+  // Sets up the layer topology for showing the effect. This involves making

[sky, 2013/08/21 21:01:01]

I don't think we've ever used topology for what this does. We typically use
hierarchy.

[rharrison, 2013/08/22 15:08:39]

Done.

+  // sure everything is on a layer and inserting clipping layers into the
+  // topology.
+  void ActivateEffect();
+
+  // Restores the layer topology and states to what they were before the effect
+  // was actived.
+  void DeactivateEffect();
+
+  void ApplyDelta(ui::Layer* frame, gfx::Rect bounds, int delta_y);

[sky, 2013/08/21 21:01:01]

const gfx::Rect& and add a description.

[rharrison, 2013/08/22 15:08:39]

Done.

+
+  BrowserView* browser_view_;  // non-owned
+  bool is_effect_active_;
+
+  scoped_ptr<ui::Layer> frame_clipping_layer_;
+  scoped_ptr<ui::Layer> web_clipping_layer_;
+  ui::Layer* web_contents_layer_;  // non-owned
+  ui::Layer* non_client_layer_;  // non-owned
+
+  // Height of the top of the window that needs to be not be occluded by the
+  // |web_clipping_layer_| so that things like the controls show through.|

[sky, 2013/08/21 21:01:01]

nuke trailing |

[rharrison, 2013/08/22 15:08:39]

Done.

+  int non_content_height_;
+
+  // Used to reparent |web_contents_layer_| when deactivating the effect.
+  ui::Layer* web_contents_parent_;  // non-owned
+
+  // Saved when the effective is activated, so it can be restored when the

[sky, 2013/08/21 21:01:01]

effective?

[rharrison, 2013/08/22 15:08:39]

Done.

+  // effect is deactivated.
+  gfx::Rect web_contents_bounds_;
+
+  // Used to turn off being on a layer when deactivating the effect.
+  views::View* non_client_view_;  // non-owned
+
+
   DISALLOW_COPY_AND_ASSIGN(ScrollEndEffectControllerAsh);
  };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_SCROLL_END_EFFECT_CONTROLLER_ASH_H_