Clean up threading around VR Scene updates.

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 "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/ui_elements.h"
@@ skipping 151 matching lines @@
   if (pixels[1] == kWebVrPosePixelMagicNumbers[0] &&
       pixels[2] == kWebVrPosePixelMagicNumbers[1]) {
     // Pose is good.
     return pixels[0];
   }
   VLOG(1) << "WebVR: reject decoded pose index " << (int)pixels[0] <<
       ", bad magic number " << (int)pixels[1] << ", " << (int)pixels[2];
   return -1;
 }
 
+int64_t TimeInMicroseconds() {
+  return std::chrono::duration_cast<std::chrono::microseconds>(
+      std::chrono::steady_clock::now().time_since_epoch()).count();
+}
+
 }  // namespace
 
 VrShellGl::VrShellGl(
     VrShell* vr_shell,
     const base::WeakPtr<VrShell>& weak_vr_shell,
     const base::WeakPtr<VrInputManager>& content_input_manager,
     const base::WeakPtr<VrInputManager>& ui_input_manager,
     scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
     gvr_context* gvr_api)
       : task_runner_(base::ThreadTaskRunnerHandle::Get()),
@@ skipping 441 matching lines @@
     // object_from_reference_matrix, we're not updating position_external.
     // TODO: Not sure what object_from_reference_matrix is. The new api removed
     // it. For now, removing it seems working fine.
     gvr_api_->ApplyNeckModel(head_pose, 1.0f);
   }
 
   frame.BindBuffer(kFramePrimaryBuffer);
 
   // Update the render position of all UI elements (including desktop).
   const float screen_tilt = kDesktopScreenTiltDefault * M_PI / 180.0f;
-  scene_->UpdateTransforms(screen_tilt, UiScene::TimeInMicroseconds());
+  scene_->UpdateTransforms(screen_tilt, TimeInMicroseconds());
 
   UpdateController(GetForwardVector(head_pose));
 
   if (vr_shell_->GetUiInterface()->GetMode() == UiInterface::Mode::WEB_VR) {
     DrawWebVr();
 
     // When using async reprojection, we need to know which pose was used in
     // the WebVR app for drawing this frame. Due to unknown amounts of
     // buffering in the compositor and SurfaceTexture, we read the pose number
     // from a corner pixel. There's no point in doing this for legacy
@@ skipping 332 matching lines @@
   }
 
   task_runner_->PostDelayedTask(FROM_HERE, draw_task_.callback(), target - now);
 }
 
 void VrShellGl::ForceExitVr() {
   main_thread_task_runner_->PostTask(
       FROM_HERE, base::Bind(&VrShell::ForceExitVr, weak_vr_shell_));
 }
 
+void VrShellGl::UpdateScene(std::unique_ptr<base::ListValue> commands) {
+  scene_->HandleCommands(std::move(commands), TimeInMicroseconds());
+}
+
 }  // namespace vr_shell