Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/browser/web_contents/web_contents_view_aura_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 "content/browser/web_contents/web_contents_view_aura.h"
 
 #include <stddef.h>
 #include <tuple>
 
 #include "base/command_line.h"
@@ skipping 366 matching lines @@
     std::unique_ptr<base::Value> value;
     value = content::ExecuteScriptAndGetValue(main_frame, "get_current()");
     if (!value->GetAsInteger(&index))
       index = -1;
     return index;
   }
 
   int ExecuteScriptAndExtractInt(const std::string& script) {
     int value = 0;
     EXPECT_TRUE(content::ExecuteScriptAndExtractInt(
-        shell()->web_contents(),
-        "domAutomationController.send(" + script + ")",
-        &value));
+        shell(), "domAutomationController.send(" + script + ")", &value));
     return value;
   }
 
   RenderViewHost* GetRenderViewHost() const {
     RenderViewHost* const rvh = shell()->web_contents()->GetRenderViewHost();
     CHECK(rvh);
     return rvh;
   }
 
   RenderWidgetHostImpl* GetRenderWidgetHost() const {
@@ skipping 729 matching lines @@
     details = dispatcher->OnEventFromSource(&release);
     ASSERT_FALSE(details.dispatcher_destroyed);
     WaitAFrame();
 
     EXPECT_LT(0, tracker.num_overscroll_updates());
     EXPECT_FALSE(tracker.overscroll_completed());
   }
 }
 
 }  // namespace content