[Mac] Confirm-to-quit: Add histogram metrics.

chrome/browser/app_controller_mac.mm

 // Copyright (c) 2011 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.
 
 #import "chrome/browser/app_controller_mac.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/mac/mac_util.h"
@@ skipping 259 matching lines @@
     browser_shutdown::SetTryingToQuit(false);
 
     // TODO(viettrungluu): Were we to remove Apple Event handlers above, we
     // would have to reinstall them here. http://crbug.com/40861
   }
 }
 
 - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication*)app {
   // Check if the preference is turned on.
   const PrefService* prefs = [self defaultProfile]->GetPrefs();
-  if (!prefs->GetBoolean(prefs::kConfirmToQuitEnabled))
+  if (!prefs->GetBoolean(prefs::kConfirmToQuitEnabled)) {
+    confirm_quit::RecordHistogram(confirm_quit::kNoConfirm);
     return NSTerminateNow;
+  }
 
   // If the application is going to terminate as the result of a Cmd+Q
   // invocation, use the special sauce to prevent accidental quitting.
   // http://dev.chromium.org/developers/design-documents/confirm-to-quit-experiment
 
   // This logic is only for keyboard-initiated quits.
   if (![ConfirmQuitPanelController eventTriggersFeature:[app currentEvent]])
     return NSTerminateNow;
 
   return [[ConfirmQuitPanelController sharedController]
@@ skipping 887 matching lines @@
 
 }  // namespace browser
 
 namespace app_controller_mac {
 
 bool IsOpeningNewWindow() {
   return g_is_opening_new_window;
 }
 
 }  // namespace app_controller_mac