Explicitly specify the ui::Compositor to DelegatedFrameHost

ui/aura/window_tree_host.cc

 // Copyright (c) 2013 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/window_tree_host.h"
 
 #include "base/debug/trace_event.h"
 #include "base/thread_task_runner_handle.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/client/cursor_client.h"
@@ skipping 163 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // WindowTreeHost, protected:
 
 WindowTreeHost::WindowTreeHost()
     : window_(new Window(NULL)),
       last_cursor_(ui::kCursorNull) {
 }
 
 void WindowTreeHost::DestroyCompositor() {
+  FOR_EACH_OBSERVER(WindowTreeHostObserver, observers_,

[sky, 2015/01/23 17:32:18]

Can whoever cares about this notification listen directly to the compositor?

[ccameron, 2015/01/23 18:52:27]

Sure (just checked that observers can be removed while traversing).

I still do like this version, but either seems fine to me.

+                    OnHostCompositorWillBeDestroyed(this));
   compositor_.reset();
 }
 
 void WindowTreeHost::DestroyDispatcher() {
   delete window_;
   window_ = NULL;
   dispatcher_.reset();
 
   // TODO(beng): this comment is no longer quite valid since this function
   // isn't called from WED, and WED isn't a subclass of Window. So it seems
@@ skipping 75 matching lines @@
   client::CursorClient* cursor_client = client::GetCursorClient(window());
   if (cursor_client) {
     const gfx::Display& display =
         gfx::Screen::GetScreenFor(window())->GetDisplayNearestWindow(window());
     cursor_client->SetDisplay(display);
   }
   dispatcher()->OnCursorMovedToRootLocation(root_location);
 }
 
 }  // namespace aura