permissionrequest API for guest Download.

android_webview/native/aw_web_contents_delegate.cc

Index: android_webview/native/aw_web_contents_delegate.cc
diff --git a/android_webview/native/aw_web_contents_delegate.cc b/android_webview/native/aw_web_contents_delegate.cc
index ef9355034abcd2f74fbec4d6421cc440a28e0209..427ffa369db6b189625bfca23f4c4d0d08d36c49 100644
--- a/android_webview/native/aw_web_contents_delegate.cc
+++ b/android_webview/native/aw_web_contents_delegate.cc
@@ -52,13 +52,15 @@ void AwWebContentsDelegate::FindReply(WebContents* web_contents,
                                                 final_update);
 }
 
-bool AwWebContentsDelegate::CanDownload(content::RenderViewHost* source,
-                                        int request_id,
-                                        const std::string& request_method) {
+void AwWebContentsDelegate::CanDownload(
+    content::RenderViewHost* source,
+    int request_id,
+    const std::string& request_method,
+    const base::Callback<void(bool)>& callback) {
   // Android webview intercepts download in its resource dispatcher host
   // delegate, so should not reach here.
   NOTREACHED();
-  return false;
+  callback.Run(false);
 }
 
 void AwWebContentsDelegate::AddNewContents(content::WebContents* source,