Add way to get native VR UI information from Java

chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/OnUiElementInfoReplyCallback.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/OnUiElementInfoReplyCallback.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/OnUiElementInfoReplyCallback.java b/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/OnUiElementInfoReplyCallback.java
new file mode 100644
index 0000000000000000000000000000000000000000..82f37e7814857627478b96ac542d3a9ffe51ccbc
--- /dev/null
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/OnUiElementInfoReplyCallback.java
@@ -0,0 +1,17 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.vr_shell;
+
+import org.json.JSONObject;
+
+import java.util.HashMap;
+
+/**
+ * Callback used to notify the caller of VrShellImpl's requestUiElementInfoFromNativeForTesting
+ * that that the requested info has been returned.
+ */
+public interface OnUiElementInfoReplyCallback {
+    void onUiElementInfoReply(HashMap<String, JSONObject> reply);
+}