Fail gracefully if InitializeResourceContext ends up calling itself recursively.

content/browser/resource_context_impl.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/browser/resource_context_impl.h"
 
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/chrome_blob_storage_context.h"
 #include "content/browser/file_system/browser_file_system_helper.h"
 #include "content/browser/in_process_webkit/webkit_context.h"
@@ skipping 61 matching lines @@
     ResourceContext* resource_context) {
   return UserDataAdapter<ChromeBlobStorageContext>::Get(
       resource_context, kBlobStorageContextKeyName);
 }
 
 HostZoomMap* GetHostZoomMapForResourceContext(ResourceContext* context) {
   return static_cast<NonOwningZoomData*>(
       context->GetUserData(kHostZoomMapKeyName))->host_zoom_map();
 }
 
 void InitializeResourceContext(BrowserContext* browser_context) {

[jam, 2012/02/23 23:11:36]

nit: perhaps rename this to EnsureResourceContextInitialized since that better
reflects its job now

   ResourceContext* resource_context = browser_context->GetResourceContext();
-  DCHECK(!resource_context->GetUserData(kWebKitContextKeyName));
+
+  if (resource_context->GetUserData(kWebKitContextKeyName))
+    return;
+
   resource_context->SetUserData(
       kWebKitContextKeyName,
       new UserDataAdapter<WebKitContext>(
           BrowserContext::GetWebKitContext(browser_context)));
   resource_context->SetUserData(
       kDatabaseTrackerKeyName,
       new UserDataAdapter<webkit_database::DatabaseTracker>(
           BrowserContext::GetDatabaseTracker(browser_context)));
   resource_context->SetUserData(
       kAppCacheServicKeyName,
@@ skipping 11 matching lines @@
 
   // This object is owned by the BrowserContext and not ResourceContext, so
   // store a non-owning pointer here.
   resource_context->SetUserData(
       kHostZoomMapKeyName,
       new NonOwningZoomData(
           HostZoomMap::GetForBrowserContext(browser_context)));
 }
 
 }  // namespace content