Add a flag to show if the FileChooserCompletion needs local paths or not.

public/web/WebFileChooserParams.h

Index: public/web/WebFileChooserParams.h
diff --git a/public/web/WebFileChooserParams.h b/public/web/WebFileChooserParams.h
index 2f8f40c652c034267c86c17768f630028166fe25..eaef311065998ff044d10fc4f093e4c128551c1c 100644
--- a/public/web/WebFileChooserParams.h
+++ b/public/web/WebFileChooserParams.h
@@ -71,12 +71,18 @@ struct WebFileChooserParams {
     // provided for compatibility reasons.
     WebString capture;
     bool useMediaCapture;
+    // Whether WebFileChooserCompletion needs local paths or not. If the result
+    // of file chooser is handled by the implementation of
+    // WebFileChooserCompletion that can handle files without local paths,
+    // 'false' should be specified to the flag.
+    bool needLocalPath;
 
     WebFileChooserParams()
         : multiSelect(false)
         , directory(false)
         , saveAs(false)
         , useMediaCapture(false)
+        , needLocalPath(true)
     {
     }
 };