Splits ToplevelWindowEventHandler into two

ash/wm/common/wm_window.h

 // Copyright 2016 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 ASH_WM_COMMON_WM_WINDOW_H_
 #define ASH_WM_COMMON_WM_WINDOW_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 168 matching lines @@
   virtual bool CanResize() const = 0;
   virtual bool CanActivate() const = 0;
 
   virtual void StackChildAtTop(WmWindow* child) = 0;
   virtual void StackChildAtBottom(WmWindow* child) = 0;
   virtual void StackChildAbove(WmWindow* child, WmWindow* target) = 0;
   virtual void StackChildBelow(WmWindow* child, WmWindow* target) = 0;
 
   virtual std::vector<WmWindow*> GetChildren() = 0;
 
+  // Shows/hides the resize shadow. |component| is the component to show the
+  // shadow for (one of the constants in ui/base/hit_test.h).
+  virtual void ShowResizeShadow(int component) = 0;
+  virtual void HideResizeShadow() = 0;
+
   // If an ancestor has been set to snap children to pixel boundaries, then
   // snaps the layer associated with this window to the layer associated with
   // the ancestor.
   virtual void SnapToPixelBoundaryIfNecessary() = 0;
 
   virtual void AddObserver(WmWindowObserver* observer) = 0;
   virtual void RemoveObserver(WmWindowObserver* observer) = 0;
 
  protected:
   virtual ~WmWindow() {}
 };
 
 }  // namespace wm
 }  // namespace ash
 
 #endif  // ASH_WM_COMMON_WM_WINDOW_H_