Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

chrome/browser/ui/webui/app_launcher_login_handler.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/webui/app_launcher_login_handler.h"
 
 #include <stddef.h>
 
 #include <string>
 
@@ skipping 121 matching lines @@
 
   // The user isn't signed in, show the sign in promo.
   signin_metrics::AccessPoint access_point =
       web_contents->GetURL().spec() == chrome::kChromeUIAppsURL
           ? signin_metrics::AccessPoint::ACCESS_POINT_APPS_PAGE_LINK
           : signin_metrics::AccessPoint::ACCESS_POINT_NTP_LINK;
   chrome::ShowBrowserSignin(browser, access_point);
   RecordInHistogram(NTP_SIGN_IN_PROMO_CLICKED);
 }
 
-void AppLauncherLoginHandler::RecordInHistogram(int type) {
-  // Invalid type to record.
-  if (type < NTP_SIGN_IN_PROMO_VIEWED ||
-      type > NTP_SIGN_IN_PROMO_CLICKED) {
-    NOTREACHED();
-  } else {
-    UMA_HISTOGRAM_ENUMERATION("SyncPromo.NTPPromo", type,
-                              NTP_SIGN_IN_PROMO_BUCKET_BOUNDARY);
-  }
+void AppLauncherLoginHandler::RecordInHistogram(NTPSignInPromoBuckets type) {
+  UMA_HISTOGRAM_ENUMERATION("SyncPromo.NTPPromo", type,
+                            NTP_SIGN_IN_PROMO_BUCKET_BOUNDARY);
 }
 
 void AppLauncherLoginHandler::HandleLoginMessageSeen(
     const base::ListValue* args) {
   Profile::FromWebUI(web_ui())->GetPrefs()->SetBoolean(
       prefs::kSignInPromoShowNTPBubble, false);
 }
 
 void AppLauncherLoginHandler::HandleShowAdvancedLoginUI(
     const base::ListValue* args) {
@@ skipping 95 matching lines @@
   values->SetString("login_status_message", message);
   values->SetString("login_status_url",
       hide_sync ? std::string() : chrome::kSyncLearnMoreURL);
   values->SetString("login_status_advanced",
       hide_sync ? base::string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_ADVANCED));
   values->SetString("login_status_dismiss",
       hide_sync ? base::string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_OK));
 }