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

chrome/browser/ui/cocoa/web_dialog_window_controller.mm

Index: chrome/browser/ui/cocoa/web_dialog_window_controller.mm
===================================================================
--- chrome/browser/ui/cocoa/web_dialog_window_controller.mm	(revision 154307)
+++ chrome/browser/ui/cocoa/web_dialog_window_controller.mm	(working copy)
@@ -74,7 +74,7 @@
   virtual content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) OVERRIDE;
-  virtual void AddNewContents(content::WebContents* source,
+  virtual bool AddNewContents(content::WebContents* source,
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
@@ -229,7 +229,7 @@
   return WebDialogWebContentsDelegate::OpenURLFromTab(source, params);
 }
 
-void WebDialogWindowDelegateBridge::AddNewContents(
+bool WebDialogWindowDelegateBridge::AddNewContents(
     content::WebContents* source,
     content::WebContents* new_contents,
     WindowOpenDisposition disposition,
@@ -237,9 +237,9 @@
     bool user_gesture) {
   if (delegate_ && delegate_->HandleAddNewContents(
           source, new_contents, disposition, initial_pos, user_gesture)) {
-    return;
+    return true;
   }
-  WebDialogWebContentsDelegate::AddNewContents(
+  return WebDialogWebContentsDelegate::AddNewContents(
       source, new_contents, disposition, initial_pos, user_gesture);
 }