X11: Remove calls to XSelectInput

ui/base/x/x11_window_event_manager.h

Index: ui/base/x/x11_window_event_manager.h
diff --git a/ui/base/x/x11_window_event_manager.h b/ui/base/x/x11_window_event_manager.h
index 0ac5a5f96c7b5517ca3c7947bc9911ef74b72189..e4bce9a62e058f7e973e4896d6d7f22f72535dc9 100644
--- a/ui/base/x/x11_window_event_manager.h
+++ b/ui/base/x/x11_window_event_manager.h
@@ -6,15 +6,12 @@
 #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;
@@ -22,6 +19,8 @@ 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 {
@@ -32,14 +31,13 @@ class UI_BASE_X_EXPORT 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();
 
@@ -63,11 +61,20 @@ class UI_BASE_X_EXPORT XWindowEventManager {
   // Updates the event mask with respect to the server, if necessary.

[Daniel Erat, 2016/09/14 04:56:10]

change this sentence to "Calls ChangeEventMask if necessary."?

[Tom (Use chromium acct), 2016/09/14 17:51:08]

Done.

   void AfterMaskChanged(XID xid, uint32_t old_mask);
 
+  // Updates the event mask of |xid| to |new_mask|, regardless of any

[Daniel Erat, 2016/09/14 04:56:10]

i was confused by this comment because it didn't make it clear that this is the
method that actually asks the X server to update the selected events (vs. e.g.
updating mask_map_, which it doesn't do). maybe this could instead be something
like "Asks the X server to set |xid|'s event mask to |new_mask|". renaming it to
SetEventMask also seems a bit clearer to me, but your call.

[Tom (Use chromium acct), 2016/09/14 17:51:08]

Done.

+  // XScopedEventSelectors that might exist.
+  void ChangeEventMask(XID xid, uint32_t new_mask);

[Daniel Erat, 2016/09/14 04:56:10]

this method doesn't need to access any members, does it? if that's correct,
please make it be a standalone function in an anonymous namespace in the .cc
file.

[Tom (Use chromium acct), 2016/09/14 17:51:08]

Done.

+
   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_