Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/browser/renderer_host/render_view_host_browsertest.cc

Index: content/browser/renderer_host/render_view_host_browsertest.cc
diff --git a/content/browser/renderer_host/render_view_host_browsertest.cc b/content/browser/renderer_host/render_view_host_browsertest.cc
index 5e14d47d46089a3986ff82dc81640afc79130100..e593e8f3c9c235547cff668b4214f4243b6ce324 100644
--- a/content/browser/renderer_host/render_view_host_browsertest.cc
+++ b/content/browser/renderer_host/render_view_host_browsertest.cc
@@ -108,7 +108,7 @@ IN_PROC_BROWSER_TEST_F(RenderViewHostTest, BasicRenderFrameHost) {
   EXPECT_TRUE(old_root->current_frame_host());
 
   ShellAddedObserver new_shell_observer;
-  EXPECT_TRUE(ExecuteScript(shell()->web_contents(), "window.open();"));
+  EXPECT_TRUE(ExecuteScript(shell(), "window.open();"));
   Shell* new_shell = new_shell_observer.GetShell();
   FrameTreeNode* new_root = static_cast<WebContentsImpl*>(
       new_shell->web_contents())->GetFrameTree()->root();
@@ -126,7 +126,7 @@ IN_PROC_BROWSER_TEST_F(RenderViewHostTest, IsFocusedElementEditable) {
 
   RenderViewHost* rvh = shell()->web_contents()->GetRenderViewHost();
   EXPECT_FALSE(rvh->IsFocusedElementEditable());
-  EXPECT_TRUE(ExecuteScript(shell()->web_contents(), "focus_textfield();"));
+  EXPECT_TRUE(ExecuteScript(shell(), "focus_textfield();"));
   EXPECT_TRUE(rvh->IsFocusedElementEditable());
 }
 
@@ -145,7 +145,7 @@ IN_PROC_BROWSER_TEST_F(RenderViewHostTest, MAYBE_ReleaseSessionOnCloseACK) {
   // Make a new Shell, a seperate tab with it's own session namespace and
   // have it start loading a url but still be in progress.
   ShellAddedObserver new_shell_observer;
-  EXPECT_TRUE(ExecuteScript(shell()->web_contents(), "window.open();"));
+  EXPECT_TRUE(ExecuteScript(shell(), "window.open();"));
   Shell* new_shell = new_shell_observer.GetShell();
   new_shell->LoadURL(test_url);
   RenderViewHost* rvh = new_shell->web_contents()->GetRenderViewHost();