Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/browser/loader/resource_dispatcher_host_browsertest.cc

Index: content/browser/loader/resource_dispatcher_host_browsertest.cc
diff --git a/content/browser/loader/resource_dispatcher_host_browsertest.cc b/content/browser/loader/resource_dispatcher_host_browsertest.cc
index 3a3a13d5550a94384a5e8d3d346ed4bb960aa980..ac8741aabe745371ecc82ba3010f14d75a0e837a 100644
--- a/content/browser/loader/resource_dispatcher_host_browsertest.cc
+++ b/content/browser/loader/resource_dispatcher_host_browsertest.cc
@@ -82,7 +82,7 @@ class ResourceDispatcherHostBrowserTest : public ContentBrowserTest,
     ShellAddedObserver new_shell_observer;
 
     // Create dynamic popup.
-    if (!ExecuteScript(shell()->web_contents(), "OpenPopup();"))
+    if (!ExecuteScript(shell(), "OpenPopup();"))
       return false;
 
     Shell* new_shell = new_shell_observer.GetShell();
@@ -189,8 +189,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest, SyncXMLHttpRequest) {
   // Let's check the XMLHttpRequest ran successfully.
   bool success = false;
   EXPECT_TRUE(ExecuteScriptAndExtractBool(
-      shell()->web_contents(),
-      "window.domAutomationController.send(DidSyncRequestSucceed());",
+      shell(), "window.domAutomationController.send(DidSyncRequestSucceed());",
       &success));
   EXPECT_TRUE(success);
 }
@@ -206,9 +205,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest,
   // Let's check the XMLHttpRequest ran successfully.
   bool success = false;
   EXPECT_TRUE(ExecuteScriptAndExtractBool(
-      shell()->web_contents(),
-      "window.domAutomationController.send(DidSucceed());",
-      &success));
+      shell(), "window.domAutomationController.send(DidSucceed());", &success));
   EXPECT_TRUE(success);
 }
 
@@ -405,10 +402,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest,
   std::string redirect_script = "window.location='" +
       test_url.possibly_invalid_spec() + "';" +
       "window.domAutomationController.send(true);";
-  EXPECT_TRUE(ExecuteScriptAndExtractBool(
-      shell()->web_contents(),
-      redirect_script,
-      &success));
+  EXPECT_TRUE(ExecuteScriptAndExtractBool(shell(), redirect_script, &success));
   EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
 }