Pass result of blockage across content API when new tab blocked.

ui/web_dialogs/web_dialog_web_contents_delegate.cc

Index: ui/web_dialogs/web_dialog_web_contents_delegate.cc
===================================================================
--- ui/web_dialogs/web_dialog_web_contents_delegate.cc	(revision 154977)
+++ ui/web_dialogs/web_dialog_web_contents_delegate.cc	(working copy)
@@ -42,7 +42,8 @@
 void WebDialogWebContentsDelegate::AddNewContents(
     WebContents* source, WebContents* new_contents,
     WindowOpenDisposition disposition, const gfx::Rect& initial_pos,
-    bool user_gesture) {
+    bool user_gesture,
+    bool* was_blocked) {
   handler_->AddNewContents(browser_context_, source, new_contents, disposition,
                            initial_pos, user_gesture);
 }