Ensure static BrowserContext methods only get called on the UI thread.

content/public/browser/browser_context.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_BROWSER_CONTEXT_H_
 #define CONTENT_PUBLIC_BROWSER_BROWSER_CONTEXT_H_
 #pragma once
 
 #include "base/hash_tables.h"
 #include "base/supports_user_data.h"
@@ skipping 26 matching lines @@
 
 class DOMStorageContext;
 class DownloadManager;
 class DownloadManagerDelegate;
 class GeolocationPermissionContext;
 class IndexedDBContext;
 class ResourceContext;
 class SpeechRecognitionPreferences;
 
 // This class holds the context needed for a browsing session.
-// It lives on the UI thread.
+// It lives on the UI thread. All these methods must only be called on the UI
+// thread.
 class CONTENT_EXPORT BrowserContext : public base::SupportsUserData {
  public:
   static DownloadManager* GetDownloadManager(BrowserContext* browser_context);
   static quota::QuotaManager* GetQuotaManager(BrowserContext* browser_context);
   static DOMStorageContext* GetDOMStorageContext(
       BrowserContext* browser_context);
   static IndexedDBContext* GetIndexedDBContext(BrowserContext* browser_context);
   static webkit_database::DatabaseTracker* GetDatabaseTracker(
       BrowserContext* browser_context);
   static appcache::AppCacheService* GetAppCacheService(
@@ skipping 76 matching lines @@
 struct hash<content::BrowserContext*> {
   std::size_t operator()(content::BrowserContext* const& p) const {
     return reinterpret_cast<std::size_t>(p);
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 #endif
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_CONTEXT_H_