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

chrome/browser/tab_contents/background_contents.h

Index: chrome/browser/tab_contents/background_contents.h
===================================================================
--- chrome/browser/tab_contents/background_contents.h	(revision 154977)
+++ chrome/browser/tab_contents/background_contents.h	(working copy)
@@ -30,11 +30,13 @@
    public:
     // Called by AddNewContents(). Asks the delegate to attach the opened
     // WebContents to a suitable container (e.g. browser) or to show it if it's
-    // a popup window.
+    // a popup window. If |was_blocked| is non-NULL, then |*was_blocked| will be
+    // set to true if the popup gets blocked, and left unchanged otherwise.
     virtual void AddWebContents(content::WebContents* new_contents,
                                 WindowOpenDisposition disposition,
                                 const gfx::Rect& initial_pos,
-                                bool user_gesture) = 0;
+                                bool user_gesture,
+                                bool* was_blocked) = 0;
 
    protected:
     virtual ~Delegate() {}
@@ -57,7 +59,8 @@
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
-                              bool user_gesture) OVERRIDE;
+                              bool user_gesture,
+                              bool* was_blocked) OVERRIDE;
 
   // content::WebContentsObserver implementation:
   virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;