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

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.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_DESKTOP_WINDOW_TREE_HOST_X11_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_X11_H_
 
 #include <X11/extensions/shape.h>
 #include <X11/Xlib.h>
 
@@ skipping 17 matching lines @@
 
 namespace ui {
 class EventHandler;
 }
 
 namespace views {
 class DesktopDragDropClientAuraX11;
 class DesktopDispatcherClient;
 class DesktopWindowTreeHostObserverX11;
 class X11DesktopWindowMoveClient;
-class X11ScopedCapture;
+class X11CaptureWindow;
 class X11WindowEventFilter;
 
 class VIEWS_EXPORT DesktopWindowTreeHostX11
     : public DesktopWindowTreeHost,
       public aura::WindowTreeHost,
       public ui::EventSource,
       public ui::PlatformEventDispatcher {
  public:
   DesktopWindowTreeHostX11(
       internal::NativeWidgetDelegate* native_widget_delegate,
@@ skipping 136 matching lines @@
   // Sends a message to the x11 window manager, enabling or disabling the
   // states |state1| and |state2|.
   void SetWMSpecState(bool enabled, ::Atom state1, ::Atom state2);
 
   // Checks if the window manager has set a specific state.
   bool HasWMSpecProperty(const char* property) const;
 
   // 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 |x11_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
   // and dispatch it to that host instead.
   void DispatchMouseEvent(ui::MouseEvent* event);
 
   // Dispatches a touch event, taking capture into account. If a different host
   // has capture, then touch-press events are translated to its coordinate space
   // and dispatched to that host instead.
   void DispatchTouchEvent(ui::TouchEvent* event);
@@ skipping 90 matching lines @@
 
   // The window shape if the window is non-rectangular.
   ::Region window_shape_;
 
   // Whether |window_shape_| was set via SetShape().
   bool custom_window_shape_;
 
   // 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_;
 
   // Whether we currently are flashing our frame. This feature is implemented
   // by setting the urgency hint with the window manager, which can draw
   // attention to the window or completely ignore the hint. We stop flashing
   // the frame when |xwindow_| gains focus or handles a mouse button event.
   bool urgency_hint_set_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostX11);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_X11_H_