Add way to get native VR UI information from Java

chrome/browser/android/vr_shell/vr_shell_gl.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/android/vr_shell/vr_shell_gl.h"
 
 #include <chrono>
 #include <limits>
+#include <string>
 #include <utility>
 
 #include "base/android/jni_android.h"
 #include "base/callback_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/android/vr_shell/mailbox_to_surface_bridge.h"
 #include "chrome/browser/android/vr_shell/ui_elements.h"
 #include "chrome/browser/android/vr_shell/ui_interface.h"
@@ skipping 314 matching lines @@
   // of the native GL context to avoid stalls later in GVR frame
   // acquire/submit.
   glFinish();
 }
 
 void VrShellGl::SetSubmitClient(
     device::mojom::VRSubmitFrameClientPtrInfo submit_client_info) {
   submit_client_.Bind(std::move(submit_client_info));
 }
 
+void VrShellGl::CreateUiElementInfos(
+    const std::vector<std::string>& element_names,
+    int callback_id,
+    base::Callback<void(int, std::unique_ptr<base::DictionaryValue>)>
+        on_created) {
+  auto reply = base::MakeUnique<base::DictionaryValue>();
+  for (const auto& name : element_names) {
+    reply->Set(name, std::move(scene_->CreateUiElementInfo(name)));
+  }
+  main_thread_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(on_created, callback_id, base::Passed(std::move(reply))));
+}
+
 void VrShellGl::OnUIFrameAvailable() {
   ui_surface_texture_->UpdateTexImage();
 }
 
 void VrShellGl::OnContentFrameAvailable() {
   content_surface_texture_->UpdateTexImage();
   received_frame_ = true;
 }
 
 void VrShellGl::OnWebVRFrameAvailable() {
@@ skipping 938 matching lines @@
   // appropriate recommended render resolution as the default size during
   // InitializeGl. Revisit if the initialization order changes.
   device::mojom::VRDisplayInfoPtr info = VrShell::CreateVRDisplayInfo(
       gvr_api_.get(), webvr_surface_size_, device_id);
   main_thread_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&RunVRDisplayInfoCallback, callback, base::Passed(&info)));
 }
 
 }  // namespace vr_shell