Have content/ create and destroy its own threads.

chrome/browser/chrome_browser_main.h

Index: chrome/browser/chrome_browser_main.h
diff --git a/chrome/browser/chrome_browser_main.h b/chrome/browser/chrome_browser_main.h
index c9f3df84a32db71bd6d60910857b52fd34d8f3ee..4cf3bb731310782713a6ccfc95f2dff2758f6bad 100644
--- a/chrome/browser/chrome_browser_main.h
+++ b/chrome/browser/chrome_browser_main.h
@@ -13,7 +13,9 @@
 #include "base/tracked_objects.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/process_singleton.h"
+#include "chrome/browser/ui/browser_init.h"
 #include "content/public/browser/browser_main_parts.h"
+#include "content/public/browser/browser_thread.h"
 
 class BrowserProcessImpl;
 class FieldTrialSynchronizer;
@@ -65,8 +67,12 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   virtual void ToolkitInitialized() OVERRIDE;
   virtual void PostMainMessageLoopStart() OVERRIDE {}
   virtual void PreMainMessageLoopRun() OVERRIDE;
+  virtual void PreMainMessageLoopRunThreadsCreated() OVERRIDE;
   virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
-  virtual void PostMainMessageLoopRun();
+  virtual void PostMainMessageLoopRun() OVERRIDE;
+  virtual void PreStopThread(content::BrowserThread::ID identifier) OVERRIDE;
+  virtual void PostStopThread(content::BrowserThread::ID identifier) OVERRIDE;
+  virtual void FinalCleanup() OVERRIDE;
 
   // Displays a warning message that we can't find any locale data files.
   virtual void ShowMissingLocaleMessageBox() = 0;
@@ -114,6 +120,7 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Methods for Main Message Loop -------------------------------------------
 
   int PreMainMessageLoopRunImpl();
+  int PreMainMessageLoopRunThreadsCreatedImpl();
 
   // Members initialized on construction ---------------------------------------
 
@@ -152,6 +159,15 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Initialized in SetupMetricsAndFieldTrials.
   scoped_refptr<FieldTrialSynchronizer> field_trial_synchronizer_;
 
+  // Members initialized in PreMainMessageLoopRun, needed in
+  // PreMainMessageLoopRunThreadsCreated.
+  bool is_first_run_;
+  bool first_run_ui_bypass_;
+  MetricsService* metrics_;
+  BrowserInit browser_init_;
+  PrefService* local_state_;
+  FilePath user_data_dir_;
+
   FRIEND_TEST(BrowserMainTest, WarmConnectionFieldTrial_WarmestSocket);
   FRIEND_TEST(BrowserMainTest, WarmConnectionFieldTrial_Random);
   FRIEND_TEST(BrowserMainTest, WarmConnectionFieldTrial_Invalid);