Context menu on views must show on mouse down for non-WIN.

ui/views/widget/widget.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_WIDGET_H_
 #define UI_VIEWS_WIDGET_WIDGET_H_
 
 #include <set>
 #include <stack>
 #include <vector>
@@ skipping 703 matching lines @@
   // Provided to allow the NativeWidget implementations to destroy the RootView
   // _before_ the focus manager/tooltip manager.
   // TODO(beng): remove once we fold those objects onto this one.
   void DestroyRootView();
 
  private:
   friend class NativeTextfieldViewsTest;
   friend class NativeComboboxViewsTest;
   friend class ScopedEvent;
 
+  class PostMousePressedProcessor;
+
   // Returns whether capture should be released on mouse release.
   virtual bool ShouldReleaseCaptureOnMouseReleased() const;
 
   // Sets the value of |disable_inactive_rendering_|. If the value changes,
   // both the NonClientView and WidgetDelegate are notified.
   void SetInactiveRenderingDisabled(bool value);
 
   // Persists the window's restored position and "show" state using the
   // window delegate.
   void SaveWindowPlacement();
@@ skipping 113 matching lines @@
   // True when window movement via mouse interaction with the frame should be
   // disabled.
   bool movement_disabled_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_WIDGET_H_