Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/test/webrtc_content_browsertest_base.cc

 // 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 "content/test/webrtc_content_browsertest_base.h"
 
 #include "base/command_line.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
@@ skipping 45 matching lines @@
 void WebRtcContentBrowserTest::AppendUseFakeUIForMediaStreamFlag() {
   base::CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kUseFakeUIForMediaStream);
 }
 
 // Executes |javascript|. The script is required to use
 // window.domAutomationController.send to send a string value back to here.
 std::string WebRtcContentBrowserTest::ExecuteJavascriptAndReturnResult(
     const std::string& javascript) {
   std::string result;
-  EXPECT_TRUE(ExecuteScriptAndExtractString(
-      shell()->web_contents(), javascript, &result))
-          << "Failed to execute javascript " << javascript << ".";
+  EXPECT_TRUE(ExecuteScriptAndExtractString(shell(), javascript, &result))
+      << "Failed to execute javascript " << javascript << ".";
   return result;
 }
 
 void WebRtcContentBrowserTest::MakeTypicalCall(const std::string& javascript,
                                                const std::string& html_file) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL(html_file));
   NavigateToURL(shell(), url);
 
@@ skipping 27 matching lines @@
       function_name,
       min_width,
       max_width,
       min_height,
       max_height,
       min_frame_rate,
       max_frame_rate);
 }
 
 }  // namespace content