Convert CrossSiteRedirectorBrowserTest to use the new navigation callbacks.

content/test/browser_test_utils_browsertest.cc

Index: content/test/browser_test_utils_browsertest.cc
diff --git a/content/test/browser_test_utils_browsertest.cc b/content/test/browser_test_utils_browsertest.cc
index 30faa2b628a6cee2bf5b4d818a70d662e5ec1df1..9303cd3d9a1d781e7e78efc07a9ca69bb112b11a 100644
--- a/content/test/browser_test_utils_browsertest.cc
+++ b/content/test/browser_test_utils_browsertest.cc
@@ -20,11 +20,9 @@ class NavigationObserver: public WebContentsObserver {
       : WebContentsObserver(web_contents) {}
   ~NavigationObserver() override {}
 
-  void DidCommitProvisionalLoadForFrame(
-      RenderFrameHost* render_frame_host,
-      const GURL& url,
-      ui::PageTransition transition_type) override {
-    navigation_url_ = url;
+  void DidFinishNavigation(NavigationHandle* navigation_handle) override {
+    if (navigation_handle->HasCommitted())

[nasko, 2017/01/27 00:25:07]

Should we use the same approach as the other CL to check it isn't an error?

[jam, 2017/01/27 00:37:08]

since
1) it doesn't matter in this case since it's a test, and it's still passing
2) the old callback would get called for the error url and it wasn't checking
that
I left it out

+      navigation_url_ = navigation_handle->GetURL();
   }
 
   void DidRedirectNavigation(NavigationHandle* handle) override {