[MD] simplify and unify some ink drop center calculations

chrome/browser/ui/views/toolbar/app_menu_button.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_TOOLBAR_APP_MENU_BUTTON_H_
 #define CHROME_BROWSER_UI_VIEWS_TOOLBAR_APP_MENU_BUTTON_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 52 matching lines @@
   // Sets |margin_trailing_| when the browser is maximized and updates layout
   // to make the focus rectangle centered.
   void SetTrailingMargin(int margin);
 
   // Opens the app menu immediately during a drag-and-drop operation.
   // Used only in testing.
   static bool g_open_app_immediately_for_testing;
 
  private:
   // views::MenuButton:
-  gfx::Point GetInkDropCenter() const override;
-
-  // views::MenuButton:
   const char* GetClassName() const override;
   scoped_ptr<views::LabelButtonBorder> CreateDefaultBorder() const override;
   gfx::Rect GetThemePaintRect() const override;
   bool GetDropFormats(
       int* formats,
       std::set<ui::Clipboard::FormatType>* format_types) override;
   bool AreDropTypesRequired() override;
   bool CanDrop(const ui::OSExchangeData& data) override;
   void OnDragEntered(const ui::DropTargetEvent& event) override;
   int OnDragUpdated(const ui::DropTargetEvent& event) override;
@@ skipping 34 matching lines @@
   // Controls the visual feedback for the button state.
   scoped_ptr<views::InkDropDelegate> ink_drop_delegate_;
 
   // Used to spawn weak pointers for delayed tasks to open the overflow menu.
   base::WeakPtrFactory<AppMenuButton> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AppMenuButton);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_TOOLBAR_APP_MENU_BUTTON_H_