Make browser_handles_top_level_requests synchronous.

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 177c153ff68cde469f63d54cbcbad32b24ebfd12..57910ec694b30b83d9692da57b4f583c0de35df7 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1614,6 +1614,16 @@ IPC_MESSAGE_ROUTED4(ViewHostMsg_OpenURL,
                     WindowOpenDisposition /* disposition */,
                     int64 /* frame id */)
 
+// Lets the browser instruct the renderer to ignore a specific navigation
+// request.
+IPC_SYNC_MESSAGE_ROUTED5_1(ViewHostMsg_ShouldIgnoreNavigation,
+                           GURL /* in - url */,
+                           content::Referrer /* in - referrer */,
+                           WindowOpenDisposition /* in - disposition */,
+                           int64 /* in - frame id */,
+                           bool /* in - is_content_initiated */,
+                           bool /* out - result */)
+
 // Notifies that the preferred size of the content changed.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidContentsPreferredSizeChange,
                     gfx::Size /* pref_size */)