Run the later parts of startup as UI thread tasks

content/browser/browser_main_runner.cc

Index: content/browser/browser_main_runner.cc
diff --git a/content/browser/browser_main_runner.cc b/content/browser/browser_main_runner.cc
index f50832af1b73afd49bf1bc7d03e45cc2e87ae2b8..36abb98960b6a6e05e22f0275c0dc1c6deb1a552 100644
--- a/content/browser/browser_main_runner.cc
+++ b/content/browser/browser_main_runner.cc
@@ -40,8 +40,9 @@ class BrowserMainRunnerImpl : public BrowserMainRunner {
       Shutdown();
   }
 
-  virtual int Initialize(const MainFunctionParams& parameters)
-      OVERRIDE {
+  virtual int Initialize(
+      const MainFunctionParams& parameters,
+      const scoped_refptr<StartupTaskRunner>& task_runner) OVERRIDE {
     TRACE_EVENT0("startup", "BrowserMainRunnerImpl::Initialize")
     is_initialized_ = true;
 
@@ -102,7 +103,7 @@ class BrowserMainRunnerImpl : public BrowserMainRunner {
 #endif
     ui::InitializeInputMethod();
 
-    main_loop_->CreateThreads();
+    main_loop_->CreateThreads(task_runner);
     int result_code = main_loop_->GetResultCode();
     if (result_code > 0)
       return result_code;