linux_aura: Improve window drag performance.

ui/views/widget/desktop_aura/x11_desktop_window_move_client.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_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_H_
 
 #include <X11/Xlib.h>
 
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
 #undef RootWindow
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop.h"
+#include "base/timer/timer.h"
 #include "ui/aura/client/window_move_client.h"
 #include "ui/gfx/point.h"
 #include "ui/views/views_export.h"
 #include "ui/views/widget/desktop_aura/x11_whole_screen_move_loop.h"
 #include "ui/views/widget/desktop_aura/x11_whole_screen_move_loop_delegate.h"
 
 namespace aura {
 class RootWindow;
 }
 
+namespace gfx {
+class Rect;
+}
+
 namespace views {
 
 // When we're dragging tabs, we need to manually position our window.
 class VIEWS_EXPORT X11DesktopWindowMoveClient :
       public views::X11WholeScreenMoveLoopDelegate,
       public aura::client::WindowMoveClient {
  public:
   X11DesktopWindowMoveClient();
   virtual ~X11DesktopWindowMoveClient();
 
   // Overridden from X11WholeScreenMoveLoopDelegate:
   virtual void OnMouseMovement(XMotionEvent* event) OVERRIDE;
   virtual void OnMouseReleased() OVERRIDE;
   virtual void OnMoveLoopEnded() OVERRIDE;
 
   // Overridden from aura::client::WindowMoveClient:
   virtual aura::client::WindowMoveResult RunMoveLoop(
       aura::Window* window,
       const gfx::Vector2d& drag_offset,
       aura::client::WindowMoveSource move_source) OVERRIDE;
   virtual void EndMoveLoop() OVERRIDE;
 
  private:
+  // Callback from |window_move_timer_|.
+  void SetHostBounds(const gfx::Rect& rect);
+
   X11WholeScreenMoveLoop move_loop_;
 
   // We need to keep track of this so we can actually move it when reacting to
   // mouse events.
   aura::RootWindow* root_window_;
 
   // Our cursor offset from the top left window origin when the drag
   // started. Used to calculate the window's new bounds relative to the current
   // location of the cursor.
   gfx::Vector2d window_offset_;
+
+  base::OneShotTimer<X11DesktopWindowMoveClient> window_move_timer_;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_H_