Enable CSS grid layout in test_shell to ease development.

webkit/tools/test_shell/webview_host_gtk.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 <gtk/gtk.h>
 
 #include "webkit/tools/test_shell/webview_host.h"
 
 #include "base/logging.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebSettings.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 #include "webkit/glue/webpreferences.h"
 #include "webkit/plugins/npapi/gtk_plugin_container.h"
 #include "webkit/tools/test_shell/test_webview_delegate.h"
 
 using WebKit::WebDevToolsAgentClient;
 using WebKit::WebView;
 
 // static
 WebViewHost* WebViewHost::Create(GtkWidget* parent_view,
                                  TestWebViewDelegate* delegate,
                                  WebDevToolsAgentClient* dev_tools_client,
                                  const webkit_glue::WebPreferences& prefs) {
   WebViewHost* host = new WebViewHost();
 
   host->view_ = WebWidgetHost::CreateWidget(parent_view, host);
   host->plugin_container_manager_.set_host_widget(host->view_);
 
   host->webwidget_ = WebView::create(delegate);
   host->webview()->setDevToolsAgentClient(dev_tools_client);
   prefs.Apply(host->webview());
+  host->webview()->settings()->setExperimentalCSSGridLayoutEnabled(true);
   host->webview()->initializeMainFrame(delegate);
   host->webwidget_->layout();
 
   return host;
 }
 
 WebView* WebViewHost::webview() const {
   return static_cast<WebView*>(webwidget_);
 }
 
 void WebViewHost::CreatePluginContainer(gfx::PluginWindowHandle id) {
   plugin_container_manager_.CreatePluginContainer(id);
 }
 
 void WebViewHost::DestroyPluginContainer(gfx::PluginWindowHandle id) {
   plugin_container_manager_.DestroyPluginContainer(id);
 }