Let input tag filter out non-native files in dropped data.

Source/core/page/DragController.cpp

Index: Source/core/page/DragController.cpp
diff --git a/Source/core/page/DragController.cpp b/Source/core/page/DragController.cpp
index 9922972e925b2faf9ce06daf72a423bef758ea09..135421d9b2133df4663031efd3907738c331b9f7 100644
--- a/Source/core/page/DragController.cpp
+++ b/Source/core/page/DragController.cpp
@@ -385,16 +385,18 @@ bool DragController::tryDocumentDrag(DragData* dragData, DragDestinationAction a
         dragSession.mouseIsOverFileInput = m_fileInputElementUnderMouse;
         dragSession.numberOfItemsToBeAccepted = 0;
 
-        unsigned numberOfFiles = dragData->numberOfFiles();
+        Vector<String> paths;
+        dragData->asFilePaths(paths);
+        const unsigned numberOfFiles = paths.size();
         if (m_fileInputElementUnderMouse) {
             if (m_fileInputElementUnderMouse->isDisabledFormControl())
                 dragSession.numberOfItemsToBeAccepted = 0;
             else if (m_fileInputElementUnderMouse->multiple())
                 dragSession.numberOfItemsToBeAccepted = numberOfFiles;
-            else if (numberOfFiles > 1)
-                dragSession.numberOfItemsToBeAccepted = 0;
-            else
+            else if (numberOfFiles == 1)
                 dragSession.numberOfItemsToBeAccepted = 1;
+            else
+                dragSession.numberOfItemsToBeAccepted = 0;
 
             if (!dragSession.numberOfItemsToBeAccepted)
                 dragSession.operation = DragOperationNone;