Mojo: Add the ability to notify a Mojo Channel that it's going to be destroyed soon.

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 904 matching lines @@
 void RenderProcessHostImpl::ResumeResponseDeferredAtStart(
     const GlobalRequestID& request_id) {
   widget_helper_->ResumeResponseDeferredAtStart(request_id);
 }
 
 void RenderProcessHostImpl::NotifyTimezoneChange() {
   Send(new ViewMsg_TimezoneChange());
 }
 
 ServiceRegistry* RenderProcessHostImpl::GetServiceRegistry() {
-  if (!mojo_application_host_)
-    return NULL;
+  DCHECK(mojo_application_host_);
   return mojo_application_host_->service_registry();
 }
 
 void RenderProcessHostImpl::AddRoute(
     int32 routing_id,
     IPC::Listener* listener) {
   listeners_.AddWithID(listener, routing_id);
 }
 
 void RenderProcessHostImpl::RemoveRoute(int32 routing_id) {
@@ skipping 977 matching lines @@
   within_process_died_observer_ = true;
   NotificationService::current()->Notify(
       NOTIFICATION_RENDERER_PROCESS_CLOSED,
       Source<RenderProcessHost>(this),
       Details<RendererClosedDetails>(&details));
   FOR_EACH_OBSERVER(RenderProcessHostObserver,
                     observers_,
                     RenderProcessExited(this, GetHandle(), status, exit_code));
   within_process_died_observer_ = false;
 
+  mojo_application_host_->WillDestroySoon();
+
   child_process_launcher_.reset();
   channel_.reset();
   gpu_message_filter_ = NULL;
   message_port_message_filter_ = NULL;
   RemoveUserData(kSessionStorageHolderKey);
 
   IDMap<IPC::Listener>::iterator iter(&listeners_);
   while (!iter.IsAtEnd()) {
     iter.GetCurrentValue()->OnMessageReceived(
         ViewHostMsg_RenderProcessGone(iter.GetCurrentKey(),
@@ skipping 82 matching lines @@
   if (pending_views_ || num_active_views > 0 || run_renderer_in_process())
     return;
 
   // Notify any contents that might have swapped out renderers from this
   // process. They should not attempt to swap them back in.
   NotificationService::current()->Notify(
       NOTIFICATION_RENDERER_PROCESS_CLOSING,
       Source<RenderProcessHost>(this),
       NotificationService::NoDetails());
 
+  mojo_application_host_->WillDestroySoon();
+
   Send(new ChildProcessMsg_Shutdown());
 }
 
 void RenderProcessHostImpl::SuddenTerminationChanged(bool enabled) {
   SetSuddenTerminationAllowed(enabled);
 }
 
 void RenderProcessHostImpl::OnDumpHandlesDone() {
   Cleanup();
 }
@@ skipping 314 matching lines @@
 }
 
 void RenderProcessHostImpl::OnDeletedGpuMemoryBuffer(
     gfx::GpuMemoryBufferType type,
     const gfx::GpuMemoryBufferId& id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   GpuMemoryBufferImpl::DeletedByChildProcess(type, id, GetHandle());
 }
 
 }  // namespace content