Implement WebVR presentation pausing for VR Shell Menu Mode

chrome/browser/android/vr_shell/vr_shell_delegate.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_delegate.h"
 
 #include "base/android/jni_android.h"
 #include "chrome/browser/android/vr_shell/vr_shell.h"
+#include "device/vr/android/gvr/gvr_device_provider.h"
 #include "jni/VrShellDelegate_jni.h"
 
 using base::android::JavaParamRef;
 using base::android::AttachCurrentThread;
 
 namespace vr_shell {
 
 // A non presenting delegate for magic window mode.
 class GvrNonPresentingDelegate : public device::GvrDelegate {
  public:
-  explicit GvrNonPresentingDelegate(jlong context) {
+  explicit GvrNonPresentingDelegate(jlong context) : weak_ptr_factory_(this) {
     gvr_api_ =
         gvr::GvrApi::WrapNonOwned(reinterpret_cast<gvr_context*>(context));
   }
 
   virtual ~GvrNonPresentingDelegate() = default;
 
   // GvrDelegate implementation
   void SetWebVRSecureOrigin(bool secure_origin) override {}
   void SubmitWebVRFrame() override {}
   void UpdateWebVRTextureBounds(int eye,
                                 float left,
                                 float top,
                                 float width,
                                 float height) override {}
   void SetGvrPoseForWebVr(const gvr::Mat4f& pose,
                           uint32_t pose_index) override {}
   gvr::GvrApi* gvr_api() override { return gvr_api_.get(); }
-
+  base::WeakPtr<GvrNonPresentingDelegate> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
  private:
   std::unique_ptr<gvr::GvrApi> gvr_api_;
+  base::WeakPtrFactory<GvrNonPresentingDelegate> weak_ptr_factory_;
 };
 
 VrShellDelegate::VrShellDelegate(JNIEnv* env, jobject obj)
     : device_provider_(nullptr) {
   j_vr_shell_delegate_.Reset(env, obj);
   GvrDelegateProvider::SetInstance(this);
 }
 
 VrShellDelegate::~VrShellDelegate() {
   GvrDelegateProvider::SetInstance(nullptr);
 }
 
-VrShellDelegate* VrShellDelegate::getNativeDelegate(
+VrShellDelegate* VrShellDelegate::GetNativeDelegate(
     JNIEnv* env, jobject jdelegate) {
   long native_delegate = Java_VrShellDelegate_getNativePointer(env, jdelegate);
   return reinterpret_cast<VrShellDelegate*>(native_delegate);
 }
 
+base::WeakPtr<device::GvrDeviceProvider> VrShellDelegate::GetDeviceProvider() {
+  return device_provider_;
+}
+
 void VrShellDelegate::ExitWebVRIfNecessary(JNIEnv* env, jobject obj) {
   if (!device_provider_)
     return;
 
   device_provider_->OnGvrDelegateRemoved();
 }
 
 bool VrShellDelegate::RequestWebVRPresent(
-    device::GvrDeviceProvider* device_provider) {
+    base::WeakPtr<device::GvrDeviceProvider> device_provider) {
   // Only set one device provider at a time
   DCHECK(!device_provider_);
   device_provider_ = device_provider;
 
   // If/When VRShell is ready for use it will call OnVrShellReady.
   JNIEnv* env = AttachCurrentThread();
   return Java_VrShellDelegate_enterVRIfNecessary(env,
                                                  j_vr_shell_delegate_.obj(),
                                                  true);
 }
 
 void VrShellDelegate::ExitWebVRPresent() {
-  if (!device_provider_)
-    return;
-
-  device_provider_ = nullptr;
+  device_provider_.reset();
 
   // VRShell is no longer needed by WebVR, allow it to shut down if it's not
   // being used elsewhere.
   JNIEnv* env = AttachCurrentThread();
   Java_VrShellDelegate_exitWebVR(env, j_vr_shell_delegate_.obj());
 }
 
-device::GvrDelegate* VrShellDelegate::GetNonPresentingDelegate() {
+base::WeakPtr<device::GvrDelegate> VrShellDelegate::GetNonPresentingDelegate() {
   if (!non_presenting_delegate_) {
     JNIEnv* env = AttachCurrentThread();
     jlong context = Java_VrShellDelegate_createNonPresentingNativeContext(
         env, j_vr_shell_delegate_.obj());
     if (!context)
       return nullptr;
 
     non_presenting_delegate_.reset(new GvrNonPresentingDelegate(context));
   }
-  return non_presenting_delegate_.get();
+  return static_cast<GvrNonPresentingDelegate*>(non_presenting_delegate_.get())
+      ->GetWeakPtr();
 }
 
 void VrShellDelegate::DestroyNonPresentingDelegate() {
   non_presenting_delegate_.reset(nullptr);
   JNIEnv* env = AttachCurrentThread();
   Java_VrShellDelegate_shutdownNonPresentingNativeContext(
       env, j_vr_shell_delegate_.obj());
 }
 
-void VrShellDelegate::OnVrShellReady(VrShell* vr_shell) {
-  if (device_provider_)
-    device_provider_->OnGvrDelegateReady(vr_shell);
-}
-
 // ----------------------------------------------------------------------------
 // Native JNI methods
 // ----------------------------------------------------------------------------
 
 bool RegisterVrShellDelegate(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   return reinterpret_cast<intptr_t>(new VrShellDelegate(env, obj));
 }
 
 }  // namespace vr_shell