Don't wait to close tabs waiting for JavaScript dialogs.

content/browser/frame_host/render_frame_host_delegate.h

Index: content/browser/frame_host/render_frame_host_delegate.h
diff --git a/content/browser/frame_host/render_frame_host_delegate.h b/content/browser/frame_host/render_frame_host_delegate.h
index d354978f79cb8387f9f76d57109048359b0ab229..28666dce8d6c76efdc122efd939ae2d51573d669 100644
--- a/content/browser/frame_host/render_frame_host_delegate.h
+++ b/content/browser/frame_host/render_frame_host_delegate.h
@@ -56,7 +56,7 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
   virtual bool OnMessageReceived(RenderFrameHost* render_frame_host,
                                  const IPC::Message& message);
 
-  // Allows the delegate to filter incoming associated inteface requests.
+  // Allows the delegate to filter incoming associated interface requests.
   virtual void OnAssociatedInterfaceRequest(
       RenderFrameHost* render_frame_host,
       const std::string& interface_name,
@@ -95,6 +95,8 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
                                       bool is_reload,
                                       IPC::Message* reply_msg) {}
 
+  virtual bool IsJavaScriptDialogShowing() const;
+
   // Called when a file selection is to be done.
   virtual void RunFileChooser(RenderFrameHost* render_frame_host,
                               const FileChooserParams& params) {}