Extract locking behaviour from ProcessSingleton.

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 ae963032e85154e3c90a88da59f5e49070da26ff..c223191fc86dc6635974a27a8dd981f54997b59f 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/chrome_browser_field_trials.h"
 #include "chrome/browser/first_run/first_run.h"
+#include "chrome/browser/modal_dialog_lock.h"
 #include "chrome/browser/process_singleton.h"
+#include "chrome/browser/process_singleton_lock.h"
 #include "chrome/browser/task_profiler/auto_tracking.h"
 #include "chrome/browser/ui/startup/startup_browser_creator.h"
 #include "content/public/browser/browser_main_parts.h"
@@ -169,6 +171,8 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
 
   // Android doesn't support multiple browser processes, so it doesn't implement
   // ProcessSingleton.
+  ProcessSingletonLock process_singleton_lock_;
+  ModalDialogLock modal_dialog_lock_;
   scoped_ptr<ProcessSingleton> process_singleton_;
 #endif
   scoped_ptr<first_run::MasterPrefs> master_prefs_;