Remove dcheck for unkonwn signin source

chrome/browser/ui/sync/one_click_signin_helper.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_helper.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 #include <vector>
@@ skipping 736 matching lines @@
                                 one_click_signin::HISTOGRAM_MAX);
       break;
     case signin::SOURCE_DEVICES_PAGE:
       UMA_HISTOGRAM_ENUMERATION("Signin.DevicesPageActions", action,
                                 one_click_signin::HISTOGRAM_MAX);
       break;
     default:
       // This switch statement needs to be updated when the enum Source changes.
       COMPILE_ASSERT(signin::SOURCE_UNKNOWN == 12,
                      kSourceEnumHasChangedButNotThisSwitchStatement);
-      NOTREACHED();
-      return;
+      UMA_HISTOGRAM_ENUMERATION("Signin.UnknownActions", action,
+                                one_click_signin::HISTOGRAM_MAX);
   }
   UMA_HISTOGRAM_ENUMERATION("Signin.AllAccessPointActions", action,
                             one_click_signin::HISTOGRAM_MAX);
 }
 
 // static
 void OneClickSigninHelper::CreateForWebContentsWithPasswordManager(
     content::WebContents* contents,
     password_manager::PasswordManager* password_manager) {
   if (!FromWebContents(contents)) {
@@ skipping 829 matching lines @@
     // If the web contents is showing a blank page and not about to be closed,
     // redirect to the NTP or apps page.
     if (signin::IsContinueUrlForWebBasedSigninFlow(current_url) &&
         !signin::IsAutoCloseEnabledInURL(original_continue_url_)) {
       RedirectToNtpOrAppsPage(
           web_contents(),
           signin::GetSourceForPromoURL(original_continue_url_));
     }
   }
 }