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

content/browser/browser_context.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.
 
 #include "content/public/browser/browser_context.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <limits>
@@ skipping 432 matching lines @@
     pid_receiver->SetPID(base::GetCurrentProcId());
 
     BrowserContextServiceManagerConnectionHolder* connection_holder =
         new BrowserContextServiceManagerConnectionHolder(
             service_manager_connection->GetConnector()->Connect(identity),
             std::move(service_request));
     browser_context->SetUserData(kServiceManagerConnection, connection_holder);
 
     ServiceManagerConnection* connection =
         connection_holder->service_manager_connection();
+    connection->Start();
 
     // New embedded service factories should be added to |connection| here.
 
     if (base::CommandLine::ForCurrentProcess()->HasSwitch(
             switches::kMojoLocalStorage)) {
       ServiceInfo info;
       info.factory =
           base::Bind(&file::CreateFileService,
                      BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE),
                      BrowserThread::GetTaskRunnerForThread(BrowserThread::DB));
       connection->AddEmbeddedService(file::mojom::kServiceName, info);
     }
 
     ContentBrowserClient::StaticServiceMap services;
     browser_context->RegisterInProcessServices(&services);
     for (const auto& entry : services) {
       connection->AddEmbeddedService(entry.first, entry.second);
     }
-    connection->Start();
   }
 }
 
 // static
 const std::string& BrowserContext::GetServiceUserIdFor(
     BrowserContext* browser_context) {
   CHECK(browser_context->GetUserData(kMojoWasInitialized))
       << "Attempting to get the mojo user id for a BrowserContext that was "
       << "never Initialize()ed.";
 
@@ skipping 40 matching lines @@
   if (GetUserData(kDownloadManagerKeyName))
     GetDownloadManager(this)->Shutdown();
 }
 
 void BrowserContext::ShutdownStoragePartitions() {
   if (GetUserData(kStoragePartitionMapKeyName))
     RemoveUserData(kStoragePartitionMapKeyName);
 }
 
 }  // namespace content