Don't expose DocumentWriter to embedding layer

Source/web/tests/WebViewTest.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1196 matching lines @@
     WebViewImpl* webViewImpl = m_webViewHelper.initialize(true, 0, &client);
 
     WebFrameImpl* frame = toWebFrameImpl(webViewImpl->mainFrame());
     client.setWebFrameClient(frame->client());
 
     WebHelperPluginImpl* helperPlugin = webViewImpl->createHelperPlugin("dummy-plugin-type", frame->document());
     EXPECT_TRUE(helperPlugin);
     EXPECT_EQ(0, helperPlugin->getPlugin()); // Invalid plugin type means no plugin.
 
     webViewImpl->closeHelperPluginSoon(helperPlugin);
+    runPendingTasks();
 
     m_webViewHelper.reset(); // Explicitly reset to break dependency on locally scoped client.
 }
 
 
 class ViewCreatingWebViewClient : public WebViewClient {
 public:
     ViewCreatingWebViewClient()
         : m_didFocusCalled(false)
     {
@@ skipping 176 matching lines @@
     WebView* webView = m_webViewHelper.initializeAndLoad(m_baseURL + "smartclip.html");
     webView->resize(WebSize(500, 500));
     webView->layout();
     WebRect cropRect(300, 125, 100, 50);
 
     // FIXME: We should test the structure of the data we get back.
     EXPECT_FALSE(webView->getSmartClipData(cropRect).isEmpty());
 }
 
 }