Implement WebVR presentation pausing for VR Shell Menu Mode

device/vr/android/gvr/gvr_device.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 "device/vr/android/gvr/gvr_device.h"
 
 #include <math.h>
 #include <algorithm>
 
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
+#include "device/vr/android/gvr/gvr_device_provider.h"
 #include "device/vr/vr_device_manager.h"
 #include "third_party/gvr-android-sdk/src/ndk/include/vr/gvr/capi/include/gvr.h"
 #include "third_party/gvr-android-sdk/src/ndk/include/vr/gvr/capi/include/gvr_types.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/transform_util.h"
 
 namespace device {
 
 namespace {
 
 static const uint64_t kPredictionTimeWithoutVsyncNanos = 50000000;
 
 }  // namespace
 
-GvrDevice::GvrDevice(GvrDeviceProvider* provider, GvrDelegate* delegate)
-    : VRDevice(provider), delegate_(delegate), gvr_provider_(provider) {}
+GvrDevice::GvrDevice(GvrDeviceProvider* provider,
+                     const base::WeakPtr<GvrDelegate>& delegate)
+    : VRDevice(), delegate_(delegate), gvr_provider_(provider) {}
 
 GvrDevice::~GvrDevice() {}
 
 mojom::VRDisplayInfoPtr GvrDevice::GetVRDevice() {
   TRACE_EVENT0("input", "GvrDevice::GetVRDevice");
 
   mojom::VRDisplayInfoPtr device = mojom::VRDisplayInfo::New();
 
   device->index = id();
 
@@ skipping 107 matching lines @@
   if (!gvr_api) {
     // If we don't have a GvrApi instance return a static forward orientation.
     pose->orientation[0] = 0.0;
     pose->orientation[1] = 0.0;
     pose->orientation[2] = 0.0;
     pose->orientation[3] = 1.0;
 
     return pose;
   }
 
+  if (!delegate_)
+    return nullptr;
+
   gvr::ClockTimePoint target_time = gvr::GvrApi::GetTimePointNow();
   target_time.monotonic_system_time_nanos += kPredictionTimeWithoutVsyncNanos;
 
   gvr::Mat4f head_mat =
       gvr_api->GetHeadSpaceFromStartSpaceRotation(target_time);
   head_mat = gvr_api->ApplyNeckModel(head_mat, 1.0f);
 
   gfx::Transform inv_transform(
       head_mat.m[0][0], head_mat.m[0][1], head_mat.m[0][2], head_mat.m[0][3],
       head_mat.m[1][0], head_mat.m[1][1], head_mat.m[1][2], head_mat.m[1][3],
@@ skipping 72 matching lines @@
     return;
 
   delegate_->UpdateWebVRTextureBounds(0,  // Left eye
                                       leftBounds->left, leftBounds->top,
                                       leftBounds->width, leftBounds->height);
   delegate_->UpdateWebVRTextureBounds(1,  // Right eye
                                       rightBounds->left, rightBounds->top,
                                       rightBounds->width, rightBounds->height);
 }
 
-void GvrDevice::SetDelegate(GvrDelegate* delegate) {
+void GvrDevice::SetDelegate(const base::WeakPtr<GvrDelegate>& delegate) {
   delegate_ = delegate;
 
   // Notify the clients that this device has changed
   if (delegate_) {
     delegate_->SetWebVRSecureOrigin(secure_origin_);
     OnDisplayChanged();
   }
 }
 
 gvr::GvrApi* GvrDevice::GetGvrApi() {
   if (!delegate_)
     return nullptr;
 
   return delegate_->gvr_api();
 }
 
 }  // namespace device