Add gesture support in views::ResizeArea

ui/views/controls/resize_area_delegate.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 UI_VIEWS_CONTROLS_RESIZE_AREA_DELEGATE_H_
 #define UI_VIEWS_CONTROLS_RESIZE_AREA_DELEGATE_H_
 
 namespace views {
 
 // An interface implemented by objects that want to be notified about the resize
 // event.
 class ResizeAreaDelegate {
  public:
   // OnResize is sent when resizing is detected. |resize_amount| specifies the
   // number of pixels that the user wants to resize by, and can be negative or
   // positive (depending on direction of dragging and flips according to
   // locale directionality: dragging to the left in LTR locales gives negative
   // |resize_amount| but positive amount for RTL). |done_resizing| is true if
-  // the user has released the mouse.
+  // the user has released the mouse/finger.

[sadrul, 2017/04/07 03:43:05]

I would change this to ".. has released the pointer (e.g. mouse, stylus, touch
etc.)"

[tdanderson, 2017/04/07 20:27:43]

Done.

   virtual void OnResize(int resize_amount, bool done_resizing) = 0;
 
  protected:
   virtual ~ResizeAreaDelegate() {}
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_RESIZE_AREA_DELEGATE_H_