Updated DropdownBarHost to use Layer clipping instead of OnPaint() clipping.

chrome/browser/ui/views/dropdown_bar_host.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 CHROME_BROWSER_UI_VIEWS_DROPDOWN_BAR_HOST_H_
 #define CHROME_BROWSER_UI_VIEWS_DROPDOWN_BAR_HOST_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/native_web_keyboard_event.h"
@@ skipping 56 matching lines @@
 
   // Shows the dropdown bar.
   virtual void Show(bool animate);
   // Hides the dropdown bar.
   virtual void Hide(bool animate);
 
   // Returns the rectangle representing where to position the dropdown widget.
   virtual gfx::Rect GetDialogPosition(gfx::Rect avoid_overlapping_rect) = 0;
 
   // Moves the widget to the provided location, moves it to top
-  // in the z-order (HWND_TOP, not HWND_TOPMOST for windows) and shows
-  // the widget (if hidden).
-  virtual void SetDialogPosition(const gfx::Rect& new_pos) = 0;
+  // in the z-order (HWND_TOP, not HWND_TOPMOST for windows), and sets the size
+  // of the |view_|.
+  virtual void SetDialogPosition(const gfx::Rect& new_pos);
 
   // Overridden from views::FocusChangeListener:
   void OnWillChangeFocus(views::View* focused_before,
                          views::View* focused_now) override;
   void OnDidChangeFocus(views::View* focused_before,
                         views::View* focused_now) override;
 
   // Overridden from ui::AcceleratorTarget:
   bool AcceleratorPressed(const ui::Accelerator& accelerator) override = 0;
   bool CanHandleAccelerators() const override = 0;
@@ skipping 35 matching lines @@
 
   // Resets the focus tracker.
   void ResetFocusTracker();
 
   // The focus manager we register with to keep track of focus changes.
   views::FocusManager* focus_manager() const { return focus_manager_; }
 
   // Returns the host widget.
   views::Widget* host() const { return host_.get(); }
 
-  // Returns the animation offset.
-  int animation_offset() const { return animation_offset_; }
-
   // Retrieves the boundary that the dropdown widget has to work with
   // within the Chrome frame window. The boundary differs depending on
   // the dropdown bar implementation. The default implementation
   // returns the boundary of browser_view and the drop down
   // can be shown in any client area.
   virtual void GetWidgetBounds(gfx::Rect* bounds);
 
   // Returns the animation for the dropdown.
   gfx::SlideAnimation* animation() {
     return animation_.get();
   }
 
  private:
   // Set the view whose position in the |browser_view_| view hierarchy
   // determines the z-order of |host_| relative to views with layers and
   // views with associated NativeViews.
   void SetHostViewNative(views::View* host_view);
 
   // The BrowserView that created us.
   BrowserView* browser_view_;
 
+  // A parent View to |view_| that is used to clip when animating the bar
+  // between the shown and hidden states.
+  views::View* clip_view_;
+
   // Our view, which is responsible for drawing the UI.
   views::View* view_;
   DropdownBarHostDelegate* delegate_;
 
-  // The y position pixel offset of the widget while animating the
-  // dropdown widget.
-  int animation_offset_;
-
   // The animation class to use when opening the Dropdown widget.
   scoped_ptr<gfx::SlideAnimation> animation_;
 
   // The focus manager we register with to keep track of focus changes.
   views::FocusManager* focus_manager_;
 
   // True if the accelerator target for Esc key is registered.
   bool esc_accel_target_registered_;
 
   // Tracks and stores the last focused view which is not the DropdownBarView
   // or any of its children. Used to restore focus once the DropdownBarView is
   // closed.
   scoped_ptr<views::ExternalFocusTracker> focus_tracker_;
 
   // Host is the Widget implementation that is created and maintained by the
   // dropdown bar. It contains the DropdownBarView.
   scoped_ptr<views::Widget> host_;
 
   // A flag to manually manage visibility. GTK/X11 is asynchronous and
   // the state of the widget can be out of sync.
   bool is_visible_;
 
   DISALLOW_COPY_AND_ASSIGN(DropdownBarHost);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_DROPDOWN_BAR_HOST_H_