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

content/browser/browser_context.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 "content/public/browser/browser_context.h"
 
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/dom_storage/dom_storage_context_impl.h"
 #include "content/browser/download/download_file_manager.h"
 #include "content/browser/download/download_manager_impl.h"
@@ skipping 26 matching lines @@
 static const char* kDownloadManagerKeyName = "download_manager";
 static const char* kFileSystemContextKeyName = "content_file_system_context";
 static const char* kIndexedDBContextKeyName = "content_indexed_db_context";
 static const char* kQuotaManagerKeyName = "content_quota_manager";
 
 namespace content {
 
 namespace {
 
 void CreateQuotaManagerAndClients(BrowserContext* context) {
+  // Ensure that these methods are called on the UI thread, except for unittests
+  // where a UI thread might not have been created.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
+         !BrowserThread::IsMessageLoopValid(BrowserThread::UI));
   if (context->GetUserData(kQuotaManagerKeyName)) {
     DCHECK(context->GetUserData(kDatabaseTrackerKeyName));
     DCHECK(context->GetUserData(kDOMStorageContextKeyName));
     DCHECK(context->GetUserData(kFileSystemContextKeyName));
     DCHECK(context->GetUserData(kIndexedDBContextKeyName));
     return;
   }
 
   // All of the clients have to be created and registered with the
   // QuotaManager prior to the QuotaManger being used. So we do them
@@ skipping 79 matching lines @@
 
 DOMStorageContextImpl* GetDOMStorageContextImpl(BrowserContext* context) {
   return static_cast<DOMStorageContextImpl*>(
       BrowserContext::GetDOMStorageContext(context));
 }
 
 }  // namespace
 
 DownloadManager* BrowserContext::GetDownloadManager(
     BrowserContext* context) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!context->GetUserData(kDownloadManagerKeyName)) {
     ResourceDispatcherHostImpl* rdh = ResourceDispatcherHostImpl::Get();
     DCHECK(rdh);
     DownloadFileManager* file_manager = rdh->download_file_manager();
     DCHECK(file_manager);
     scoped_refptr<DownloadManager> download_manager =
         new DownloadManagerImpl(
             file_manager,
             scoped_ptr<DownloadItemFactory>(),
             GetContentClient()->browser()->GetNetLog());
@@ skipping 101 matching lines @@
   }
 
   if (GetUserData(kDOMStorageContextKeyName))
     GetDOMStorageContextImpl(this)->Shutdown();
 
   if (GetUserData(kDownloadManagerKeyName))
     GetDownloadManager(this)->Shutdown();
 }
 
 }  // namespace content