X11: Remove calls to XSelectInput

ui/base/x/x11_window_event_manager.h

 // Copyright 2016 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_BASE_X_X11_WINDOW_EVENT_MANAGER_H_
 #define UI_BASE_X_X11_WINDOW_EVENT_MANAGER_H_
 
 #include <map>
-#include <vector>
 
-#include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "ui/base/x/ui_base_x_export.h"
 #include "ui/gfx/x/x11_types.h"
 
-// A process wide singleton for selecting events on X windows which were not
-// created by Chrome.
 namespace base {
 template <typename T>
 struct DefaultSingletonTraits;
 }
 
 namespace ui {
 
+class XWindowEventManager;
+
 // Ensures events in |event_mask| are selected on |xid| for the duration of this
 // object's lifetime.
 class UI_BASE_X_EXPORT XScopedEventSelector {
  public:
   XScopedEventSelector(XID xid, uint32_t event_mask);
   ~XScopedEventSelector();
 
  private:
   XID xid_;
   uint32_t event_mask_;
+  base::WeakPtr<XWindowEventManager> event_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(XScopedEventSelector);
 };
 
-// Manages the events that Chrome has selected on X windows which were not
-// created by Chrome. This class allows multiple clients within Chrome to select
-// events on the same X window.
-class UI_BASE_X_EXPORT XWindowEventManager {
+// Allows multiple clients within Chrome to select events on the same X window.
+class XWindowEventManager {
  public:
   static XWindowEventManager* GetInstance();
 
  private:
   friend struct base::DefaultSingletonTraits<XWindowEventManager>;
   friend class XScopedEventSelector;
 
   class MultiMask;
 
   XWindowEventManager();
   ~XWindowEventManager();
 
   // Guarantees that events in |event_mask| will be reported to Chrome.
   void SelectEvents(XID xid, uint32_t event_mask);
 
   // Deselects events on |event_mask|.  Chrome will stop receiving events for
   // any set bit in |event_mask| only if no other client has selected that bit.
   void DeselectEvents(XID xid, uint32_t event_mask);
 
-  // Called whenever the mask corresponding to window |xid| might have changed.
-  // Updates the event mask with respect to the server, if necessary.
+  // Helper method called by SelectEvents and DeselectEvents whenever the mask
+  // corresponding to window |xid| might have changed.  Calls SetEventMask if
+  // necessary.
   void AfterMaskChanged(XID xid, uint32_t old_mask);
 
   std::map<XID, std::unique_ptr<MultiMask>> mask_map_;
 
+  // This is used to set XScopedEventSelector::event_manager_.  If |this| is
+  // destroyed before any XScopedEventSelector, the |event_manager_| will become
+  // invalidated.
+  base::WeakPtrFactory<XWindowEventManager> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(XWindowEventManager);
 };
 
 }  // namespace ui
 
-#endif  // UI_BASE_X_X11_FOREIGN_WINDOW_MANAGER_H_
+#endif  // UI_BASE_X_X11_WINDOW_EVENT_MANAGER_H_