Implement initial version of scroll end effect

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

Index: chrome/browser/ui/views/frame/contents_container.h
diff --git a/chrome/browser/ui/views/frame/contents_container.h b/chrome/browser/ui/views/frame/contents_container.h
index cfd6d9a2e16d0d2eff3ab310045e7815bc269174..72779ee7af750671ea342f4e788b5962037e3193 100644
--- a/chrome/browser/ui/views/frame/contents_container.h
+++ b/chrome/browser/ui/views/frame/contents_container.h
@@ -9,13 +9,20 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/compositor/layer.h"
+#include "ui/gfx/rect.h"
 #include "ui/views/view.h"
 
+namespace views {
+class WebView;
+}
+
 // ContentsContainer is responsible for managing the active WebContents view.
 // ContentsContainer has one child: the currently active WebContents.
 class ContentsContainer : public views::View {
  public:
-  explicit ContentsContainer(views::View* active_web_view);
+  explicit ContentsContainer(views::WebView* active_web_view);
   virtual ~ContentsContainer();
 
   // Sets the active top margin; the active WebView's y origin would be
@@ -24,17 +31,34 @@ class ContentsContainer : public views::View {
   // if the margin changed and this view needs Layout().
   bool SetActiveTopMargin(int margin);
 
+  // Fast-resize is used for |active_web_view_| while the scroll-end effect is
+  // active. It also prevents the bounds of the contents from being updated by
+  // layouts of this class.
+  virtual void ActivateScrollEndEffect();
+  virtual void DeactivateScrollEndEffect();
+
+  virtual void UpdateScrollEndEffectHeightDelta(int height_delta,
+                                                bool scrolling_down);
+
   // Overridden from views::View:
   virtual void Layout() OVERRIDE;
   virtual const char* GetClassName() const OVERRIDE;
 
  private:
-  views::View* active_web_view_;
+  views::WebView* active_web_view_;
 
   // The margin between the top and the active view. This is used to make the
   // find bar overlap the detached bookmark bar on the new tab page.
   int active_top_margin_;
 
+  // When the effect is active the web contents will not have its bounds
+  // adjusted on layout and instead will just be clipped.
+  bool scroll_effect_active_;
+
+  // Stores the bounds of the web_view before the scroll end effect starts. This
+  // allows for restoring the bounds of the view at the end of the effect.
+  gfx::Rect web_view_bounds_;
+
   DISALLOW_COPY_AND_ASSIGN(ContentsContainer);
 };