Add way to get native VR UI information from Java

chrome/browser/android/vr_shell/vr_shell.h

Index: chrome/browser/android/vr_shell/vr_shell.h
diff --git a/chrome/browser/android/vr_shell/vr_shell.h b/chrome/browser/android/vr_shell/vr_shell.h
index 7a3de3000f39c4ee92d3cc28a4516f973d1463f3..09b4fcbb73236c050c763da767766ed5104803a2 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -128,6 +128,11 @@ class VrShell : public device::GvrDelegate,
                                 const base::android::JavaParamRef<jobject>& obj,
                                 jboolean can_go_back,
                                 jboolean can_go_forward);
+  void RequestUiElementInfoForTesting(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jobjectArray element_names,
+      jint callback_id);
 
   void ContentWebContentsDestroyed();
   // Called when our WebContents have been hidden. Usually a sign that something
@@ -167,6 +172,8 @@ class VrShell : public device::GvrDelegate,
   // Perform a UI action triggered by the javascript API.
   void DoUiAction(const UiAction action,
                   const base::DictionaryValue* arguments);
+  void OnUiElementInfoCreated(int callback_id,
+                              std::unique_ptr<base::DictionaryValue> info);
 
   void SetContentCssSize(float width, float height, float dpr);
   void SetUiCssSize(float width, float height, float dpr);