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

chrome/browser/ui/sync/one_click_signin_sync_starter.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/sync/one_click_signin_sync_starter.h"
 
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 411 matching lines @@
       default:
         DisplayFinalConfirmationBubble(l10n_util::GetStringUTF16(
             IDS_SYNC_ERROR_SIGNING_IN));
         break;
     }
   }
   delete this;
 }
 
 void OneClickSigninSyncStarter::SigninSuccess() {
+  const GURL& current_url = web_contents()->GetURL();

[Roger Tawa OOO till Jul 10th, 2015/12/03 18:18:06]

It seems the web contents could be null sometimes.  I think it might be safer to
pass the access point and reason to the ctor and save them as members.

[gogerald1, 2015/12/03 19:03:18]

Done.

+  signin_metrics::LogSigninAccessPointCompleted(
+      signin::GetAccessPointForPromoURL(current_url));
+  signin_metrics::LogSigninReason(
+      signin::GetSigninReasonForPromoURL(current_url));
 }
 
 void OneClickSigninSyncStarter::AccountAddedToCookie(
     const GoogleServiceAuthError& error) {
   // Regardless of whether the account was successfully added or not,
   // continue with sync starting.
 
   if (!sync_setup_completed_callback_.is_null())
     sync_setup_completed_callback_.Run(SYNC_SETUP_SUCCESS);
 
@@ skipping 163 matching lines @@
                                             false /* user_gesture */);
 }
 
 void OneClickSigninSyncStarter::LoadContinueUrl() {
   web_contents()->GetController().LoadURL(
       continue_url_,
       content::Referrer(),
       ui::PAGE_TRANSITION_AUTO_TOPLEVEL,
       std::string());
 }