Tidy DEFINE_(THREAD_SAFE_)STATIC_LOCAL() implementations.

third_party/WebKit/Source/core/layout/LayoutTestHelper.cpp

 // Copyright 2014 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 "core/layout/LayoutTestHelper.h"
 
 #include "core/frame/FrameHost.h"
 #include "core/html/HTMLIFrameElement.h"
 #include "platform/loader/fetch/MemoryCache.h"
 #include "platform/scroll/ScrollbarTheme.h"
@@ skipping 14 matching lines @@
 
   return m_child.get();
 }
 
 void FrameLoaderClientWithParent::detached(FrameDetachType) {
   static_cast<SingleChildFrameLoaderClient*>(parent()->client())
       ->didDetachChild();
 }
 
 ChromeClient& RenderingTest::chromeClient() const {
-  DEFINE_STATIC_LOCAL(EmptyChromeClient, client, (EmptyChromeClient::create()));
+  // |ChromeClient| contains a weak reference to a |Node| (which derives
+  // from |ScriptWrappable|). That reference is only used for unit testing
+  // purposes and will not accidentally leak between contexts. Consequently,
+  // disable the singleton verification check.
+  DEFINE_STATIC_LOCAL(EmptyChromeClient, client, (EmptyChromeClient::create()),
+                      CheckScriptWrappable::No);
   return client;
 }
 
 RenderingTest::RenderingTest(FrameLoaderClient* frameLoaderClient)
     : m_frameLoaderClient(frameLoaderClient) {}
 
 void RenderingTest::SetUp() {
   Page::PageClients pageClients;
   fillWithEmptyClients(pageClients);
   pageClients.chromeClient = &chromeClient();
@@ skipping 19 matching lines @@
   // Clear memory cache, otherwise we can leak pruned resources.
   memoryCache()->evictResources();
 }
 
 void RenderingTest::setChildFrameHTML(const String& html) {
   childDocument().setBaseURLOverride(KURL(ParsedURLString, "http://test.com"));
   childDocument().body()->setInnerHTML(html, ASSERT_NO_EXCEPTION);
 }
 
 }  // namespace blink