Remove unused DidOpenURL api from WebContentObserver.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index e4e4e6d7ccd0b3881dd0b5398fbb1d93ae68bea5..6b3f0e1dcf9a4bdab04ad20aa9afc85348adf4fd 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1561,10 +1561,6 @@ WebContents* WebContentsImpl::OpenURL(const OpenURLParams& params) {
     return NULL;
 
   WebContents* new_contents = delegate_->OpenURLFromTab(this, params);
-  // Notify observers.
-  FOR_EACH_OBSERVER(WebContentsObserver, observers_,
-                    DidOpenURL(params.url, params.referrer,
-                               params.disposition, params.transition));
   return new_contents;
 }