Hides ink ripple when a button drag is started

ui/views/view.cc

 // Copyright (c) 2012 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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 1267 matching lines @@
   return ui::DragDropTypes::DRAG_NONE;
 }
 
 void View::OnDragExited() {
 }
 
 int View::OnPerformDrop(const ui::DropTargetEvent& event) {
   return ui::DragDropTypes::DRAG_NONE;
 }
 
+void View::OnDragStarted(const ui::LocatedEvent& event) {
+}
+
 void View::OnDragDone() {
 }
 
 // static
 bool View::ExceededDragThreshold(const gfx::Vector2d& delta) {
   return (abs(delta.x()) > GetHorizontalDragThreshold() ||
           abs(delta.y()) > GetVerticalDragThreshold());
 }
 
 // Accessibility----------------------------------------------------------------
@@ skipping 1075 matching lines @@
   Widget* widget = GetWidget();
   // We should only start a drag from an event, implying we have a widget.
   DCHECK(widget);
 
   // Don't attempt to start a drag while in the process of dragging. This is
   // especially important on X where we can get multiple mouse move events when
   // we start the drag.
   if (widget->dragged_view())
     return false;
 
+  OnDragStarted(event);
+
   OSExchangeData data;
   WriteDragData(press_pt, &data);
 
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views