Extract minimal RenderViewHost interface for embedders, leaving

content/browser/accessibility/renderer_accessibility_browsertest.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 <string>
 #include <vector>
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/test/base/in_process_browser_test.h"
@@ skipping 22 matching lines @@
   RendererAccessibilityBrowserTest() {}
 
   // Tell the renderer to send an accessibility tree, then wait for the
   // notification that it's been received.
   const WebAccessibility& GetWebAccessibilityTree() {
     ui_test_utils::WindowedNotificationObserver tree_updated_observer(
         content::NOTIFICATION_RENDER_VIEW_HOST_ACCESSIBILITY_TREE_UPDATED,
         content::NotificationService::AllSources());
     content::RenderWidgetHostView* host_view =
         browser()->GetSelectedWebContents()->GetRenderWidgetHostView();
-    RenderWidgetHostImpl* host = static_cast<RenderWidgetHostImpl*>(
-        host_view->GetRenderWidgetHost());
-    RenderViewHost* view_host = static_cast<RenderViewHost*>(host);
+    RenderWidgetHostImpl* host =
+        RenderWidgetHostImpl::From(host_view->GetRenderWidgetHost());
+    RenderViewHostImpl* view_host = static_cast<RenderViewHostImpl*>(host);
     view_host->set_save_accessibility_tree_for_testing(true);
     view_host->EnableRendererAccessibility();
     tree_updated_observer.Wait();
     return view_host->accessibility_tree_for_testing();
   }
 
   // Make sure each node in the tree has an unique id.
   void RecursiveAssertUniqueIds(
       const WebAccessibility& node, base::hash_set<int>* ids) {
     ASSERT_TRUE(ids->find(node.id) == ids->end());
@@ skipping 400 matching lines @@
   const WebAccessibility& tree = GetWebAccessibilityTree();
 
   ASSERT_EQ(1U, tree.children.size());
   const WebAccessibility& textbox = tree.children[0];
 
   EXPECT_EQ(
       true, GetBoolAttr(textbox, WebAccessibility::ATTR_CAN_SET_VALUE));
 }
 
 }  // namespace