Clarify wording around blocking 3rd party cookies and add lab to block reading of 3rd party cookies

webkit/tools/test_shell/simple_resource_loader_bridge.cc

 // Copyright (c) 2010 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.
 //
 // This file contains an implementation of the ResourceLoaderBridge class.
 // The class is implemented using net::URLRequest, meaning it is a "simple"
 // version that directly issues requests. The more complicated one used in the
 // browser uses IPC.
 //
 // Because net::URLRequest only provides an asynchronous resource loading API,
@@ skipping 148 matching lines @@
 
     if (g_request_context) {
       g_request_context->Release();
       g_request_context = NULL;
     }
   }
 
   void SetAcceptAllCookies(bool accept_all_cookies) {
     StaticCookiePolicy::Type policy_type = accept_all_cookies ?
         StaticCookiePolicy::ALLOW_ALL_COOKIES :
-        StaticCookiePolicy::BLOCK_THIRD_PARTY_COOKIES;
+        StaticCookiePolicy::BLOCK_SETTING_THIRD_PARTY_COOKIES;
     static_cast<StaticCookiePolicy*>(g_request_context->cookie_policy())->
         set_type(policy_type);
   }
 };
 
 IOThread* g_io_thread = NULL;
 
 //-----------------------------------------------------------------------------
 
 struct RequestParams {
@@ skipping 748 matching lines @@
 
 // static
 scoped_refptr<base::MessageLoopProxy>
     SimpleResourceLoaderBridge::GetIoThread() {
   if (!EnsureIOThread()) {
     LOG(DFATAL) << "Failed to create IO thread.";
     return NULL;
   }
   return g_io_thread->message_loop_proxy();
 }