SupportsUserData is not thread safe

content/browser/in_process_webkit/indexed_db_browsertest.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 "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/process_util.h"
@@ skipping 175 matching lines @@
 };
 
 IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTestWithGCExposed,
                        DatabaseCallbacksTest) {
   SimpleTest(GetTestUrl("indexeddb", "database_callbacks_first.html"));
 }
 
 class IndexedDBBrowserTestWithVersion0Schema : public IndexedDBBrowserTest {
  public:
   virtual void SetUpOnMainThread() {
+    scoped_refptr<IndexedDBContext> context =
+        BrowserContext::GetIndexedDBContext(
+            shell()->web_contents()->GetBrowserContext());
     BrowserThread::PostTask(
         BrowserThread::WEBKIT_DEPRECATED, FROM_HERE,
         base::Bind(
             &IndexedDBBrowserTestWithVersion0Schema::CopyLevelDBToProfile,
-            shell()));
+            shell(),
+            context));
     scoped_refptr<base::ThreadTestHelper> helper(
         new base::ThreadTestHelper(BrowserThread::GetMessageLoopProxyForThread(
             BrowserThread::WEBKIT_DEPRECATED)));
     ASSERT_TRUE(helper->Run());
   }
-  static void CopyLevelDBToProfile(Shell* shell) {
+  static void CopyLevelDBToProfile(Shell* shell,
+                                   scoped_refptr<IndexedDBContext> context) {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT_DEPRECATED));
     FilePath leveldb_dir(FILE_PATH_LITERAL("file__0.indexeddb.leveldb"));
     FilePath test_data_dir =
         GetTestFilePath("indexeddb", "migration_from_0").Append(leveldb_dir);
-    IndexedDBContext* context = BrowserContext::GetIndexedDBContext(
-        shell->web_contents()->GetBrowserContext());
     IndexedDBContextImpl* context_impl =
-        static_cast<IndexedDBContextImpl*>(context);
+        static_cast<IndexedDBContextImpl*>(context.get());
     FilePath dest = context_impl->data_path().Append(leveldb_dir);
     // If we don't create the destination directory first, the contents of the
     // leveldb directory are copied directly into profile/IndexedDB instead of
     // profile/IndexedDB/file__0.xxx/
     ASSERT_TRUE(file_util::CreateDirectory(dest));
     const bool kRecursive = true;
     ASSERT_TRUE(file_util::CopyDirectory(test_data_dir,
                                          context_impl->data_path(),
                                          kRecursive));
   }
@@ skipping 49 matching lines @@
   TitleWatcher title_watcher(new_shell->web_contents(), expected_title16);
 
   base::KillProcess(
       shell()->web_contents()->GetRenderProcessHost()->GetHandle(), 0, true);
   shell()->Close();
 
   EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
 }
 
 }  // namespace content