Implement newly designed sign-in related histograms for desktop platorms.

chrome/browser/ui/cocoa/extensions/extension_installed_bubble_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/extensions/extension_installed_bubble_controller.h"
 
 #include "base/i18n/rtl.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 206 matching lines @@
   DCHECK([self bubbleReference]);
   bool didClose =
       [self bubbleReference]->CloseBubble(BUBBLE_CLOSE_USER_DISMISSED);
   DCHECK(didClose);
 }
 
 - (BOOL)textView:(NSTextView*)aTextView
    clickedOnLink:(id)link
          atIndex:(NSUInteger)charIndex {
   DCHECK_EQ(promo_.get(), aTextView);
-  chrome::ShowBrowserSignin(browser_,
-                            signin_metrics::SOURCE_EXTENSION_INSTALL_BUBBLE);
+  chrome::ShowBrowserSignin(
+      browser_,
+      signin_metrics::AccessPoint::ACCESS_POINT_EXTENSION_INSTALL_BUBBLE);
   return YES;
 }
 
 // Extracted to a function here so that it can be overridden for unit testing.
 - (void)removePageActionPreviewIfNecessary {
   if (![self extension] || !pageActionPreviewShowing_)
     return;
   ExtensionAction* page_action =
       extensions::ExtensionActionManager::Get(browser_->profile())->
       GetPageAction(*[self extension]);
@@ skipping 414 matching lines @@
   [self close];
 }
 
 - (void)awakeFromNib {
   if (bundle_)
     return;
   [self initializeLabel];
 }
 
 @end