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

Source/core/html/forms/FileInputType.cpp

Index: Source/core/html/forms/FileInputType.cpp
diff --git a/Source/core/html/forms/FileInputType.cpp b/Source/core/html/forms/FileInputType.cpp
index e26e55da239b8c0b749554b755b74ad80afc1be9..342cc44006a2a48b553df8b5ea4c014d2a6f5ef1 100644
--- a/Source/core/html/forms/FileInputType.cpp
+++ b/Source/core/html/forms/FileInputType.cpp
@@ -333,10 +333,21 @@ void FileInputType::receiveDropForDirectoryUpload(const Vector<String>& paths)
     }
 }
 
+void FileInputType::getAcceptableDropFileNames(const DragData& dragData, Vector<String>* result)
+{
+    result->clear();
+    Vector<String> paths;
+    dragData.asFilenames(paths);
+    for (const String path : paths) {
+        if (!path.isEmpty())
+            result->append(path);
+    }
+}
+
 bool FileInputType::receiveDroppedFiles(const DragData* dragData)
 {
     Vector<String> paths;
-    dragData->asFilenames(paths);
+    FileInputType::getAcceptableDropFileNames(*dragData, &paths);
     if (paths.isEmpty())
         return false;