Add metrics to keep track of the tab activate/deactivate cycle

chrome/browser/ui/ash/launcher/browser_status_monitor.cc

Index: chrome/browser/ui/ash/launcher/browser_status_monitor.cc
diff --git a/chrome/browser/ui/ash/launcher/browser_status_monitor.cc b/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
index 002dc296b607f0717585af1b4b264581dd454bee..119bad52220375722e530bc12056e194fb54cd93 100644
--- a/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
+++ b/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
@@ -256,7 +256,8 @@ void BrowserStatusMonitor::TabReplacedAt(TabStripModel* tab_strip_model,
   AddWebContentsObserver(new_contents);
 }
 
-void BrowserStatusMonitor::TabInsertedAt(content::WebContents* contents,
+void BrowserStatusMonitor::TabInsertedAt(TabStripModel* tab_strip_model,
+                                         content::WebContents* contents,
                                          int index,
                                          bool foreground) {
   // An inserted tab is not active - ActiveTabChanged() will be called to