VR: Prevent WebVR from receiving poses while in VR browsing mode.

This CL is kept intentionally as simple as possible for merging back to
M-63.

Tests to prevent this regression in the future will be added in a
followup CL.

Bug: 775571
Change-Id: I78ea1e46efdb2b48bc61e1ab704b6b1526d2c171
Reviewed-on: https://chromium-review.googlesource.com/723770Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509606}

chrome/browser/android/vr_shell/vr_shell_delegate.cc

@@ -79,6 +79,10 @@ VrShellDelegate* VrShellDelegate::GetNativeVrShellDelegate(
 void VrShellDelegate::SetDelegate(VrShell* vr_shell,
                                   gvr::ViewerType viewer_type) {
   vr_shell_ = vr_shell;
+  device::GvrDevice* device = static_cast<device::GvrDevice*>(GetDevice());
+  if (device)
+    device->SetInBrowsingMode(true);
+
   if (pending_successful_present_request_) {
     CHECK(!present_callback_.is_null());
     base::ResetAndReturn(&present_callback_).Run(true);
@@ -90,9 +94,11 @@ void VrShellDelegate::SetDelegate(VrShell* vr_shell,
 
 void VrShellDelegate::RemoveDelegate() {
   vr_shell_ = nullptr;
-  device::VRDevice* device = GetDevice();
-  if (device)
+  device::GvrDevice* device = static_cast<device::GvrDevice*>(GetDevice());
+  if (device) {
+    device->SetInBrowsingMode(false);
     device->OnExitPresent();
+  }
 }
 
 void VrShellDelegate::SetPresentResult(JNIEnv* env,
@@ -170,6 +176,11 @@ void VrShellDelegate::Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj) {
 
 void VrShellDelegate::SetDeviceId(unsigned int device_id) {
   device_id_ = device_id;
+  if (vr_shell_) {
+    device::GvrDevice* device = static_cast<device::GvrDevice*>(GetDevice());
+    if (device)
+      device->SetInBrowsingMode(true);
+  }
 }
 
 void VrShellDelegate::RequestWebVRPresent(

device/vr/android/gvr/gvr_device.cc

@@ -182,6 +182,10 @@ void GvrDevice::ExitPresent() {
 
 void GvrDevice::GetPose(
     mojom::VRMagicWindowProvider::GetPoseCallback callback) {
+  if (in_browsing_mode_) {
+    std::move(callback).Run(nullptr);
+    return;
+  }
   std::move(callback).Run(
       GvrDelegate::GetVRPosePtrWithNeckModel(gvr_api_.get(), nullptr));
 }

device/vr/android/gvr/gvr_device.h

@@ -42,6 +42,11 @@ class DEVICE_VR_EXPORT GvrDevice : public VRDeviceBase {
   void Activate(mojom::VRDisplayEventReason reason,
                 base::Callback<void(bool)> on_handled);
 
+  // TODO(mthiesse): Make this functionality cross-platform.
+  void SetInBrowsingMode(bool in_browsing_mode) {
+    in_browsing_mode_ = in_browsing_mode;
+  }
+
  private:
   void OnListeningForActivate(bool listening) override;
   void OnRequestPresentResult(
@@ -54,6 +59,7 @@ class DEVICE_VR_EXPORT GvrDevice : public VRDeviceBase {
 
   base::android::ScopedJavaGlobalRef<jobject> non_presenting_context_;
   std::unique_ptr<gvr::GvrApi> gvr_api_;
+  bool in_browsing_mode_ = false;
 
   base::WeakPtrFactory<GvrDevice> weak_ptr_factory_;