Revert Change ServiceManagerConnectionImpl to run service request handlers on the IO thread

content/browser/service_manager/service_manager_context.cc

Index: content/browser/service_manager/service_manager_context.cc
diff --git a/content/browser/service_manager/service_manager_context.cc b/content/browser/service_manager/service_manager_context.cc
index c400726c1c84c109691fb8abe0e8234fb2138f97..a398ae9a5d1a36c9d2b413870f8daa7cbdb06777 100644
--- a/content/browser/service_manager/service_manager_context.cc
+++ b/content/browser/service_manager/service_manager_context.cc
@@ -53,31 +53,40 @@ base::LazyInstance<std::unique_ptr<service_manager::Connector>>::Leaky
 
 void DestroyConnectorOnIOThread() { g_io_thread_connector.Get().reset(); }
 
-void StartServiceInUtilityProcess(
-    const std::string& service_name,
+void StartUtilityProcessOnIOThread(
+    service_manager::mojom::ServiceFactoryRequest request,
     const base::string16& process_name,
-    bool use_sandbox,
-    service_manager::mojom::ServiceRequest request) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+    bool use_sandbox) {
   UtilityProcessHost* process_host =
       UtilityProcessHost::Create(nullptr, nullptr);
   process_host->SetName(process_name);
   if (!use_sandbox)
     process_host->DisableSandbox();
   process_host->Start();
+  process_host->GetRemoteInterfaces()->GetInterface(std::move(request));
+}
+
+void StartServiceInUtilityProcess(
+    const std::string& service_name,
+    const base::string16& process_name,
+    bool use_sandbox,
+    service_manager::mojom::ServiceRequest request) {
   service_manager::mojom::ServiceFactoryPtr service_factory;
-  process_host->GetRemoteInterfaces()->GetInterface(
-      mojo::MakeRequest(&service_factory));
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&StartUtilityProcessOnIOThread,
+                 base::Passed(MakeRequest(&service_factory)), process_name,
+                 use_sandbox));
   service_factory->CreateService(std::move(request), service_name);
 }
 
 #if (ENABLE_MOJO_MEDIA_IN_GPU_PROCESS)
 
 // Request service_manager::mojom::ServiceFactory from GPU process host. Must be
-// called on IO thread.
-void StartServiceInGpuProcess(const std::string& service_name,
-                              service_manager::mojom::ServiceRequest request) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+// called on
+// IO thread.
+void RequestGpuServiceFactory(
+    service_manager::mojom::ServiceFactoryRequest request) {
   GpuProcessHost* process_host =
       GpuProcessHost::Get(GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED);
   if (!process_host) {
@@ -85,13 +94,20 @@ void StartServiceInGpuProcess(const std::string& service_name,
     return;
   }
 
-  service_manager::mojom::ServiceFactoryPtr service_factory;
   // TODO(xhwang): It's possible that |process_host| is non-null, but the actual
   // process is dead. In that case, |request| will be dropped and application
   // load requests through ServiceFactory will also fail. Make sure we handle
   // these cases correctly.
-  process_host->GetRemoteInterfaces()->GetInterface(
-      mojo::MakeRequest(&service_factory));
+  process_host->GetRemoteInterfaces()->GetInterface(std::move(request));
+}
+
+void StartServiceInGpuProcess(const std::string& service_name,
+                              service_manager::mojom::ServiceRequest request) {
+  service_manager::mojom::ServiceFactoryPtr service_factory;
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&RequestGpuServiceFactory,
+                 base::Passed(MakeRequest(&service_factory))));
   service_factory->CreateService(std::move(request), service_name);
 }
 
@@ -285,12 +301,13 @@ ServiceManagerContext::ServiceManagerContext() {
       std::move(root_browser_service), mojo::MakeRequest(&pid_receiver));
   pid_receiver->SetPID(base::GetCurrentProcId());
 
+  packaged_services_connection_->Start();
+  ServiceManagerConnection::GetForProcess()->Start();
 
   ServiceInfo device_info;
   device_info.factory =
       base::Bind(&device::CreateDeviceService,
                  BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE));
-  device_info.task_runner = base::ThreadTaskRunnerHandle::Get();
   packaged_services_connection_->AddEmbeddedService(device::mojom::kServiceName,
                                                     device_info);
 
@@ -334,8 +351,6 @@ ServiceManagerContext::ServiceManagerContext() {
   packaged_services_connection_->AddServiceRequestHandler(
       "media", base::Bind(&StartServiceInGpuProcess, "media"));
 #endif
-  packaged_services_connection_->Start();
-  ServiceManagerConnection::GetForProcess()->Start();
 }
 
 ServiceManagerContext::~ServiceManagerContext() {