Consolidates accessing and setting the UMA pref to be within metrics code

chrome/browser/extensions/api/preference/preference_api.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/extensions/api/preference/preference_api.h"
 
 #include <map>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 78 matching lines @@
     {"safeBrowsingEnabled", prefs::kSafeBrowsingEnabled,
      APIPermission::kPrivacy, APIPermission::kPrivacy},
     {"searchSuggestEnabled", prefs::kSearchSuggestEnabled,
      APIPermission::kPrivacy, APIPermission::kPrivacy},
     {"spellingServiceEnabled", prefs::kSpellCheckUseSpellingService,
      APIPermission::kPrivacy, APIPermission::kPrivacy},
     {"thirdPartyCookiesAllowed", prefs::kBlockThirdPartyCookies,
      APIPermission::kPrivacy, APIPermission::kPrivacy},
     {"translationServiceEnabled", prefs::kEnableTranslate,
      APIPermission::kPrivacy, APIPermission::kPrivacy},
+    {"metricsReportingEnabled", prefs::kMetricsReportingEnabled,
+     APIPermission::kPrivacy, APIPermission::kPrivacy},
 #if defined(OS_CHROMEOS)
     {"autoclick", prefs::kAccessibilityAutoclickEnabled,
      APIPermission::kAccessibilityFeaturesRead,
      APIPermission::kAccessibilityFeaturesModify},
     {"highContrast", prefs::kAccessibilityHighContrastEnabled,
      APIPermission::kAccessibilityFeaturesRead,
      APIPermission::kAccessibilityFeaturesModify},
     {"largeCursor", prefs::kAccessibilityLargeCursorEnabled,
      APIPermission::kAccessibilityFeaturesRead,
      APIPermission::kAccessibilityFeaturesModify},
@@ skipping 603 matching lines @@
           pref_key, PreferenceFunction::PERMISSION_TYPE_WRITE, &browser_pref)) {
     return false;
   }
 
   PreferenceAPI::Get(GetProfile())
       ->RemoveExtensionControlledPref(extension_id(), browser_pref, scope);
   return true;
 }
 
 }  // namespace extensions