Add a total startup counter

With this counter of all startups, you can now use metrics to compute ratios of sessions.  Also add some UMA to the tracking file.

TEST=not this time
BUG= no

Review URL: http://codereview.chromium.org/6281009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72277 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/about_flags.cc

@@ -535,6 +535,7 @@ void RecordUMAStatistics(const PrefService* prefs) {
   // stats can be made meaningful.
   if (flags.size())
     UserMetrics::RecordAction(UserMetricsAction("AboutFlags_StartupTick"));
+  UserMetrics::RecordAction(UserMetricsAction("StartupTick"));
 }
 
 //////////////////////////////////////////////////////////////////////////////

chrome/tools/chromeactions.txt

@@ -1026,6 +1026,7 @@
 0x3b86156dcf560cdb	ShowSections_RecentSitesEnabled
 0x5118181c3ece5e84	ShowSessions
 0x26f93e6e68e28a69	Star
+0x2fbe99005588ef01	StartupTick
 0x11a755d598c0c417	Stop
 0x926a51baad949d12	Strikethrough
 0x4d56afb0a9837d41	TabContextMenu_BookmarkAllTabs