Convert chrome_url_data_manager (previously a global) into a Singleton. This

chrome/browser/browser_about_handler.cc

Index: chrome/browser/browser_about_handler.cc
diff --git a/chrome/browser/browser_about_handler.cc b/chrome/browser/browser_about_handler.cc
index 428a9d24e2cc7d6f5c558d398d95dbe2565c2007..370cfa08d7c84596c4f79340a97b57b874b401ce 100644
--- a/chrome/browser/browser_about_handler.cc
+++ b/chrome/browser/browser_about_handler.cc
@@ -568,7 +568,7 @@ AboutSource::AboutSource()
 
   // Add us to the global URL handler on the IO thread.
   g_browser_process->io_thread()->message_loop()->PostTask(FROM_HERE,
-      NewRunnableMethod(&chrome_url_data_manager,
+      NewRunnableMethod(Singleton<ChromeURLDataManager>().get(),
           &ChromeURLDataManager::AddDataSource, this));
 }