Remove RenderViewHost parameter from WebContentsObserver::Did{Start|Stop}Loading.

content/public/test/browser_test_utils.cc

Index: content/public/test/browser_test_utils.cc
diff --git a/content/public/test/browser_test_utils.cc b/content/public/test/browser_test_utils.cc
index 6ac4f13a9e79ed51e1c3ef7ff26c05d70e011fd0..afb07ba6c226136d23bb0506370082e0035dccef 100644
--- a/content/public/test/browser_test_utils.cc
+++ b/content/public/test/browser_test_utils.cc
@@ -795,7 +795,7 @@ const base::string16& TitleWatcher::WaitAndGetTitle() {
   return observed_title_;
 }
 
-void TitleWatcher::DidStopLoading(RenderViewHost* render_view_host) {
+void TitleWatcher::DidStopLoading() {
   // When navigating through the history, the restored NavigationEntry's title
   // will be used. If the entry ends up having the same title after we return
   // to it, as will usually be the case, then WebContentsObserver::TitleSet