Move Mojo channel initialization closer to IPC::Channel setup

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index a1fb9f888cb71d3ae2f3d4634843fc2a2ac517bf..9474f58ce481045ba62b5dc54744d442218da73d 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -87,7 +87,6 @@
 #include "content/browser/renderer_host/pepper/pepper_message_filter.h"
 #include "content/browser/renderer_host/pepper/pepper_renderer_connection.h"
 #include "content/browser/renderer_host/render_message_filter.h"
-#include "content/browser/renderer_host/render_process_host_mojo_impl.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_helper.h"
@@ -113,6 +112,8 @@
 #include "content/common/child_process_messages.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/gpu/gpu_messages.h"
+#include "content/common/mojo/mojo_channel_init.h"
+#include "content/common/mojo/mojo_messages.h"
 #include "content/common/resource_messages.h"
 #include "content/common/view_messages.h"
 #include "content/port/browser/render_widget_host_view_frame_subscriber.h"
@@ -138,6 +139,7 @@
 #include "ipc/ipc_logging.h"
 #include "ipc/ipc_switches.h"
 #include "media/base/media_switches.h"
+#include "mojo/embedder/platform_channel_pair.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "ppapi/shared_impl/ppapi_switches.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ -169,6 +171,15 @@ static const char* kSiteProcessMapKeyName = "content_site_process_map";
 namespace content {
 namespace {
 
+base::PlatformFile PlatformFileFromScopedPlatformHandle(
+    mojo::embedder::ScopedPlatformHandle handle) {
+#if defined(OS_POSIX)
+  return handle.release().fd;
+#elif defined(OS_WIN)
+  return handle.release().handle;
+#endif
+}
+
 void CacheShaderInfo(int32 id, base::FilePath path) {
   ShaderCacheFactory::GetInstance()->SetCacheInfo(id, path);
 }
@@ -548,6 +559,7 @@ bool RenderProcessHostImpl::Init() {
                                 this,
                                 BrowserThread::GetMessageLoopProxyForThread(
                                     BrowserThread::IO).get()));
+  InitializeMojo();
 
   // Call the embedder first so that their IPC filters have priority.
   GetContentClient()->browser()->RenderProcessWillLaunch(this);
@@ -608,6 +620,31 @@ bool RenderProcessHostImpl::Init() {
   return true;
 }
 
+void RenderProcessHostImpl::InitializeMojo() {
+  mojo::embedder::PlatformChannelPair channel_pair;
+  mojo_channel_init_.reset(new MojoChannelInit);
+
+  mojo::ScopedMessagePipeHandle message_pipe = mojo_channel_init_->Init(
+      PlatformFileFromScopedPlatformHandle(channel_pair.PassServerHandle()),
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
+  DCHECK(message_pipe.is_valid());
+
+  // The render_process_ is ready to use at this point, but all calls will be
+  // queued until the client-side is connected. See ActivateMojo.
+  render_process_.reset(
+      ScopedIRenderProcessHandle::From(message_pipe.Pass()), this);
+
+  // Forward this to the client once we know its process handle.
+  mojo_client_handle_ = channel_pair.PassClientHandle();
+}
+
+void RenderProcessHostImpl::ActivateMojo() {
+  base::PlatformFile client_file =
+      PlatformFileFromScopedPlatformHandle(mojo_client_handle_.Pass());
+  Send(new MojoMsg_Activate(
+           IPC::GetFileHandleForProcess(client_file, GetHandle(), true)));
+}
+
 void RenderProcessHostImpl::CreateMessageFilters() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   AddFilter(new ResourceSchedulerFilter(GetID()));
@@ -1917,7 +1954,8 @@ void RenderProcessHostImpl::ProcessDied(bool already_dead) {
 
   ClearTransportDIBCache();
 
-  render_process_host_mojo_.reset();
+  render_process_.reset();
+  mojo_channel_init_.reset();
 
   // It's possible that one of the calls out to the observers might have caused
   // this object to be no longer needed.
@@ -2052,6 +2090,10 @@ void RenderProcessHostImpl::OnProcessLaunched() {
       Source<RenderProcessHost>(this),
       NotificationService::NoDetails());
 
+  // Let the Mojo system get setup on the child process side before any other
+  // IPCs arrive. This way those may safely generate Mojo-related RPCs.
+  ActivateMojo();
+
   while (!queued_messages_.empty()) {
     Send(queued_messages_.front());
     queued_messages_.pop();
@@ -2061,9 +2103,6 @@ void RenderProcessHostImpl::OnProcessLaunched() {
   if (WebRTCInternals::GetInstance()->aec_dump_enabled())
     EnableAecDump(WebRTCInternals::GetInstance()->aec_dump_file_path());
 #endif
-
-  if (render_process_host_mojo_.get())
-    render_process_host_mojo_->OnProcessLaunched();
 }
 
 scoped_refptr<AudioRendererHost>
@@ -2140,9 +2179,8 @@ void RenderProcessHostImpl::DecrementWorkerRefCount() {
 void RenderProcessHostImpl::SetWebUIHandle(
     int32 view_routing_id,
     mojo::ScopedMessagePipeHandle handle) {
-  if (!render_process_host_mojo_)
-    render_process_host_mojo_.reset(new RenderProcessHostMojoImpl(this));
-  render_process_host_mojo_->SetWebUIHandle(view_routing_id, handle.Pass());
+  DCHECK(!render_process_.is_null());
+  render_process_->SetWebUIHandle(view_routing_id, handle.Pass());
 }
 
 }  // namespace content