Allow VRDisplay to specify which frame the layer bounds should be updated at.

chrome/browser/android/vr_shell/non_presenting_gvr_delegate.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_NON_PRESENTING_GVR_DELEGATE_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_NON_PRESENTING_GVR_DELEGATE_H_
 
 #include <jni.h>
 
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
 #include "device/vr/vr_service.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace vr_shell {
 
 // A non presenting delegate for magic window mode.
 class NonPresentingGvrDelegate : public device::GvrDelegate,
                                  public device::mojom::VRVSyncProvider {
  public:
   explicit NonPresentingGvrDelegate(long context);
 
   ~NonPresentingGvrDelegate();
 
   // GvrDelegate implementation
   void SetWebVRSecureOrigin(bool secure_origin) override {}
   void SubmitWebVRFrame() override {}
-  void UpdateWebVRTextureBounds(const gvr::Rectf& left_bounds,
+  void UpdateWebVRTextureBounds(int16_t frame_index,
+                                const gvr::Rectf& left_bounds,
                                 const gvr::Rectf& right_bounds) override {}
   void SetWebVRRenderSurfaceSize(int width, int height) override {}
   gvr::Sizei GetWebVRCompositorSurfaceSize() override {
-    return device::kInvalidRenderTargetSize; }
+    return device::kInvalidRenderTargetSize;
+  }
   gvr::GvrApi* gvr_api() override { return gvr_api_.get(); }
   void OnVRVsyncProviderRequest(
       device::mojom::VRVSyncProviderRequest request) override;
   void UpdateVSyncInterval(long timebase_nanos,
                            double interval_seconds) override;
 
   void Pause();
   void Resume();
   device::mojom::VRVSyncProviderRequest OnSwitchToPresentingDelegate();
 
  private:
   void StopVSyncLoop();
   void StartVSyncLoop();
   void OnVSync();
-  void GetVSync(const GetVSyncCallback& callback);
-  device::mojom::VRPosePtr GetPose();
+  void SendVSync(const base::TimeDelta& time, GetVSyncCallback callback);

[dcheng, 2017/01/18 23:58:07]

Nit: pass by value. It's also convention to pass copyable callbacks by const ref
generally -- is there a reason to do otherwise here?

[mthiesse, 2017/01/19 01:19:08]

Done.

The reason I wasn't passing by const ref is so that I could move callback_ and
not have to explicitly Reset() it. Doesn't matter to me either way.

+
+  // VRVSyncProvider implementation
+  void GetVSync(const GetVSyncCallback& callback) override;
 
   std::unique_ptr<gvr::GvrApi> gvr_api_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::CancelableClosure vsync_task_;
   base::TimeTicks vsync_timebase_;
   base::TimeDelta vsync_interval_;
 
   bool paused_ = false;
   base::TimeDelta pending_time_;
   bool pending_vsync_ = false;
   GetVSyncCallback callback_;
   bool received_frame_ = false;
-  uint32_t pose_index_ = 1;
   mojo::Binding<device::mojom::VRVSyncProvider> binding_;
   base::WeakPtrFactory<NonPresentingGvrDelegate> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NonPresentingGvrDelegate);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_NON_PRESENTING_GVR_DELEGATE_H_