Add a histogram to record time elapsed before we start the browser message loop.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6853023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@81775 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/browser_main.h b/chrome/browser/browser_main.h
index ae27721..41e6f95 100644
--- a/chrome/browser/browser_main.h
+++ b/chrome/browser/browser_main.h
@@ -172,4 +172,8 @@
 // present on the current platform.
 void WarnAboutMinimumSystemRequirements();
 
+// Records the time from our process' startup to the present time in
+// the UMA histogram |metric_name|.
+void RecordBrowserStartupTime();
+
 #endif  // CHROME_BROWSER_BROWSER_MAIN_H_