Move Mojo channel initialization closer to IPC::Channel setup

content/renderer/mojo/mojo_render_process_observer.cc

Index: content/renderer/mojo/mojo_render_process_observer.cc
diff --git a/content/renderer/mojo/mojo_render_process_observer.cc b/content/renderer/mojo/mojo_render_process_observer.cc
index 7f01d3f8a691f761b13b648642e7334b4b0adf40..f1abb37b5b76957a8d5894a925977a404244dbc2 100644
--- a/content/renderer/mojo/mojo_render_process_observer.cc
+++ b/content/renderer/mojo/mojo_render_process_observer.cc
@@ -24,7 +24,7 @@ bool MojoRenderProcessObserver::OnControlMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(MojoRenderProcessObserver, message)
-    IPC_MESSAGE_HANDLER(MojoMsg_ChannelCreated, OnChannelCreated)
+    IPC_MESSAGE_HANDLER(MojoMsg_Activate, OnActivate)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -38,7 +38,7 @@ MojoRenderProcessObserver::~MojoRenderProcessObserver() {
   render_thread_->RemoveObserver(this);
 }
 
-void MojoRenderProcessObserver::OnChannelCreated(
+void MojoRenderProcessObserver::OnActivate(
     const IPC::PlatformFileForTransit& file) {
 #if defined(OS_POSIX)
   base::PlatformFile handle = file.fd;
@@ -47,14 +47,13 @@ void MojoRenderProcessObserver::OnChannelCreated(
 #endif
   DCHECK(!channel_init_.get());
   channel_init_.reset(new MojoChannelInit);
-  channel_init_->Init(handle, ChildProcess::current()->io_message_loop_proxy());
-  if (!channel_init_->is_handle_valid())
-    return;
+  mojo::ScopedMessagePipeHandle message_pipe =
+      channel_init_->Init(handle,
+                          ChildProcess::current()->io_message_loop_proxy());
+  DCHECK(message_pipe.is_valid());
 
-  ScopedRenderProcessHostMojoHandle render_process_host_handle(
-      RenderProcessHostMojoHandle(
-          channel_init_->bootstrap_message_pipe().release().value()));
-  render_process_host_mojo_.reset(render_process_host_handle.Pass(), this);
+  render_process_host_.reset(
+      ScopedIRenderProcessHostHandle::From(message_pipe.Pass()), this);
 }
 
 void MojoRenderProcessObserver::SetWebUIHandle(