Do not release capture when transferring capture between Chrome windows on Linux

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
index c16ef57c964e32a57cc299d0beafc3725734754f..0eba6c4bc54339ab6b2bcd2f93d7f127d07aa64e 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
@@ -37,7 +37,7 @@ class DesktopDragDropClientAuraX11;
 class DesktopDispatcherClient;
 class DesktopWindowTreeHostObserverX11;
 class X11DesktopWindowMoveClient;
-class X11ScopedCapture;
+class X11CaptureWindow;
 class X11WindowEventFilter;
 
 class VIEWS_EXPORT DesktopWindowTreeHostX11
@@ -167,6 +167,9 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   virtual ui::EventProcessor* GetEventProcessor() OVERRIDE;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(DesktopWindowTreeHostX11InteractiveUITest,
+                           SynchronousCapture);
+
   // Initializes our X11 surface to draw on. This method performs all
   // initialization related to talking to the X11 server.
   void InitX11Window(const Widget::InitParams& params);
@@ -197,9 +200,9 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   // Sets whether the window's borders are provided by the window manager.
   void SetUseNativeFrame(bool use_native_frame);
 
-  // Called when another DRWHL takes capture, or when capture is released
-  // entirely.
-  void OnCaptureReleased();
+  // Releases |capture_window_| so that it can be used by another
+  // DesktopWindowTreeHostX11.
+  scoped_ptr<X11CaptureWindow> ReleaseCaptureWindow();
 
   // Dispatches a mouse event, taking mouse capture into account. If a
   // different host has capture, we translate the event to its coordinate space
@@ -318,18 +321,15 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   // The size of the window manager provided borders (if any).
   gfx::Insets native_window_frame_borders_;
 
-  // The current root window host that has capture. While X11 has something
-  // like Windows SetCapture()/ReleaseCapture(), it is entirely implicit and
-  // there are no notifications when this changes. We need to track this so we
-  // can notify widgets when they have lost capture, which controls a bunch of
-  // things in views like hiding menus.
+  // The current DesktopWindowTreeHostX11 which has capture. Set synchronously
+  // when capture is requested via SetCapture().
   static DesktopWindowTreeHostX11* g_current_capture;
 
   // A list of all (top-level) windows that have been created but not yet
   // destroyed.
   static std::list<XID>* open_windows_;
 
-  scoped_ptr<X11ScopedCapture> x11_capture_;
+  scoped_ptr<X11CaptureWindow> capture_window_;
 
   base::string16 window_title_;