Support exposing Mojo services between render frames, render threads, and their respective hosts.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index e66bd926caa120ba4bdba4ce5d523db9f365493e..ba379174c084dea27eee5631149a842f882d6e29 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -51,7 +51,7 @@
 #include "content/common/gpu/client/gpu_memory_buffer_impl.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/gpu/gpu_process_launch_causes.h"
-#include "content/common/mojo/mojo_service_names.h"
+#include "content/common/render_frame_setup.mojom.h"
 #include "content/common/resource_messages.h"
 #include "content/common/view_messages.h"
 #include "content/common/worker_messages.h"
@@ -92,7 +92,6 @@
 #include "content/renderer/service_worker/embedded_worker_context_message_filter.h"
 #include "content/renderer/service_worker/embedded_worker_dispatcher.h"
 #include "content/renderer/shared_worker/embedded_shared_worker_stub.h"
-#include "content/renderer/web_ui_setup_impl.h"
 #include "grit/content_resources.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_forwarding_message_filter.h"
@@ -265,6 +264,28 @@ void NotifyTimezoneChangeOnThisThread() {
   v8::Date::DateTimeConfigurationChangeNotification(isolate);
 }
 
+class RenderFrameSetupImpl : public mojo::InterfaceImpl<RenderFrameSetup> {
+ public:
+  virtual void GetServiceProvider(
+      int32_t frame_routing_id,
+      mojo::InterfaceRequest<mojo::IInterfaceProvider> request) OVERRIDE {
+    RenderFrameImpl* frame = RenderFrameImpl::FromRoutingID(frame_routing_id);
+    if (!frame) {

[darin (slow to review), 2014/06/21 04:33:35]

Under what conditions is there no frame yet for this routing ID? Is there
some race condition you are dealing with here? Some comments would be
helpful. I'm also curious if we could avoid the complexity of
RegisterPendingRenderFrameConnect somehow.

[Sam McNally, 2014/06/24 04:00:29]

There's a race between the IPC that causes the RenderFrame to be created and the
Mojo message for GetServiceProviderForFrame. It seems to hit this condition for
top-level frames created after the first one. The delayed Mojo activation is
probably giving us the better ordering for the first frame.

Passing the handle in the other direction may fix the problem in this case, but
I suspect there are some other cases where it would be racy in the other
direction.

I think we may be stuck with this until we can enforce ordering between the two
messages or send the handle with the create message.

+      RenderThreadImpl::current()->RegisterPendingRenderFrameConnect(
+          frame_routing_id, request.PassMessagePipe());
+      return;
+    }
+
+    frame->BindServiceRegistry(request.PassMessagePipe());
+  }
+
+  virtual void OnConnectionError() OVERRIDE { delete this; }
+};
+
+void CreateRenderFrameSetup(mojo::InterfaceRequest<RenderFrameSetup> request) {
+  mojo::BindToRequest(new RenderFrameSetupImpl(), &request);
+}
+
 }  // namespace
 
 RenderThreadImpl::HistogramCustomizer::HistogramCustomizer() {
@@ -507,10 +528,19 @@ void RenderThreadImpl::Init() {
     }
   }
 
+  service_registry()->AddService<RenderFrameSetup>(
+      base::Bind(CreateRenderFrameSetup));
+
   TRACE_EVENT_END_ETW("RenderThreadImpl::Init", 0, "");
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
+  for (std::map<int, mojo::MessagePipeHandle>::iterator it =
+           pending_render_frame_connects_.begin();
+       it != pending_render_frame_connects_.end();
+       ++it) {
+    mojo::ScopedMessagePipeHandle handle(it->second);

[darin (slow to review), 2014/06/21 04:33:35]

nit: again, CloseRaw() might be clearer.

[Sam McNally, 2014/06/24 04:00:29]

Done.

+  }
 }
 
 void RenderThreadImpl::Shutdown() {
@@ -679,6 +709,18 @@ scoped_refptr<base::MessageLoopProxy>
 
 void RenderThreadImpl::AddRoute(int32 routing_id, IPC::Listener* listener) {
   ChildThread::GetRouter()->AddRoute(routing_id, listener);
+  std::map<int, mojo::MessagePipeHandle>::iterator it =
+      pending_render_frame_connects_.find(routing_id);
+  if (it == pending_render_frame_connects_.end())
+    return;
+
+  RenderFrameImpl* frame = RenderFrameImpl::FromRoutingID(routing_id);
+  if (!frame)
+    return;
+
+  mojo::ScopedMessagePipeHandle handle(it->second);
+  pending_render_frame_connects_.erase(it);
+  frame->BindServiceRegistry(handle.Pass());
 }
 
 void RenderThreadImpl::RemoveRoute(int32 routing_id) {
@@ -702,6 +744,15 @@ void RenderThreadImpl::RemoveEmbeddedWorkerRoute(int32 routing_id) {
   }
 }
 
+void RenderThreadImpl::RegisterPendingRenderFrameConnect(
+    int routing_id,
+    mojo::ScopedMessagePipeHandle handle) {
+  std::pair<std::map<int, mojo::MessagePipeHandle>::iterator, bool> result =
+      pending_render_frame_connects_.insert(
+          std::make_pair(routing_id, handle.release()));
+  CHECK(result.second) << "Inserting a duplicate item.";
+}
+
 int RenderThreadImpl::GenerateRoutingID() {
   int routing_id = MSG_ROUTING_NONE;
   Send(new ViewHostMsg_GenerateRoutingID(&routing_id));
@@ -1094,6 +1145,10 @@ void RenderThreadImpl::ReleaseCachedFonts() {
 
 #endif  // OS_WIN
 
+ServiceRegistry* RenderThreadImpl::GetServiceRegistry() {
+  return service_registry();
+}
+
 bool RenderThreadImpl::IsMainThread() {
   return !!current();
 }
@@ -1174,19 +1229,6 @@ scoped_ptr<gfx::GpuMemoryBuffer> RenderThreadImpl::AllocateGpuMemoryBuffer(
       .PassAs<gfx::GpuMemoryBuffer>();
 }
 
-void RenderThreadImpl::ConnectToService(
-    const mojo::String& service_url,
-    const mojo::String& service_name,
-    mojo::ScopedMessagePipeHandle message_pipe,
-    const mojo::String& requestor_url) {
-  // TODO(darin): Invent some kind of registration system to use here.
-  if (service_url.To<base::StringPiece>() == kRendererService_WebUISetup) {
-    WebUISetupImpl::Bind(message_pipe.Pass());
-  } else {
-    NOTREACHED() << "Unknown service name";
-  }
-}
-
 void RenderThreadImpl::DoNotSuspendWebKitSharedTimer() {
   suspend_webkit_shared_timer_ = false;
 }