aura-x11: Install the dispatcher as a message-pump observer.

ui/aura/dispatcher_linux.cc

 // 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.
 
 #include "ui/aura/dispatcher_linux.h"
 
 #include <X11/extensions/XInput2.h>
 
 #include "ui/base/events.h"
 
@@ skipping 21 matching lines @@
     }
   }
 }
 
 }  // namespace
 
 namespace aura {
 
 DispatcherLinux::DispatcherLinux() {
   base::MessagePumpX::SetDefaultDispatcher(this);
+  MessageLoopForUI::current()->AddObserver(this);
 }
 
 DispatcherLinux::~DispatcherLinux() {
+  MessageLoopForUI::current()->RemoveObserver(this);
   base::MessagePumpX::SetDefaultDispatcher(NULL);
 }
 
 void DispatcherLinux::WindowDispatcherCreated(
     ::Window window,
     MessageLoop::Dispatcher* dispatcher) {
   dispatchers_.insert(std::make_pair(window, dispatcher));
 }
 
 void DispatcherLinux::WindowDispatcherDestroying(::Window window) {
   dispatchers_.erase(window);
 }
 
 bool DispatcherLinux::Dispatch(const base::NativeEvent& xev) {
-  PreprocessXEvent(xev);
-
   // XI_HierarchyChanged events are special. There is no window associated with
   // these events. So process them directly from here.
   if (xev->type == GenericEvent &&
       xev->xgeneric.evtype == XI_HierarchyChanged) {
     ui::UpdateDeviceList();
     return true;
   }
 
   // MappingNotify events (meaning that the keyboard or pointer buttons have
   // been remapped) aren't associated with a window; send them to all
   // dispatchers.
   if (xev->type == MappingNotify) {
     for (DispatchersMap::const_iterator it = dispatchers_.begin();
          it != dispatchers_.end(); ++it) {
       it->second->Dispatch(xev);
     }
     return true;
   }
 
   MessageLoop::Dispatcher* dispatcher = GetDispatcherForXEvent(xev);
   return dispatcher ? dispatcher->Dispatch(xev) : true;
 }
 
+base::EventStatus DispatcherLinux::WillProcessEvent(
+    const base::NativeEvent& event) {
+  PreprocessXEvent(event);
+  return base::EVENT_CONTINUE;
+}
+
+void DispatcherLinux::DidProcessEvent(const base::NativeEvent& event) {
+}
+
 MessageLoop::Dispatcher* DispatcherLinux::GetDispatcherForXEvent(
     XEvent* xev) const {
   ::Window window = xev->xany.window;
   if (xev->type == GenericEvent) {
     XIDeviceEvent* xievent = static_cast<XIDeviceEvent*>(xev->xcookie.data);
     window = xievent->event;
   }
   DispatchersMap::const_iterator it = dispatchers_.find(window);
   return it != dispatchers_.end() ? it->second : NULL;
 }
 
 MessageLoop::Dispatcher* CreateDispatcher() {
   return new DispatcherLinux;
 }
 
 }  // namespace aura