Add desktop engagement metrics.

chrome/browser/ui/browser_list.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/browser_list.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 210 matching lines @@
   content::RecordAction(UserMetricsAction("ActiveBrowserChanged"));
 
   RemoveBrowserFrom(browser, &GetInstance()->last_active_browsers_);
   GetInstance()->last_active_browsers_.push_back(browser);
 
   FOR_EACH_OBSERVER(chrome::BrowserListObserver, observers_.Get(),
                     OnBrowserSetLastActive(browser));
 }
 
 // static
+void BrowserList::NotifyBrowserNoLongerActive(Browser* browser) {
+  FOR_EACH_OBSERVER(chrome::BrowserListObserver, observers_.Get(),
+                    OnBrowserNoLongerActive(browser));
+}
+
+// static
 bool BrowserList::IsIncognitoSessionActive() {
   for (auto* browser : *BrowserList::GetInstance()) {
     if (browser->profile()->IsOffTheRecord())
       return true;
   }
   return false;
 }
 
 // static
 bool BrowserList::IsIncognitoSessionActiveForProfile(Profile* profile) {
@@ skipping 16 matching lines @@
 }
 
 // static
 void BrowserList::RemoveBrowserFrom(Browser* browser,
                                     BrowserVector* browser_list) {
   BrowserVector::iterator remove_browser =
       std::find(browser_list->begin(), browser_list->end(), browser);
   if (remove_browser != browser_list->end())
     browser_list->erase(remove_browser);
 }