Switch WebVR to handle GvrApi management through VrShellDelegate

chrome/browser/android/vr_shell/vr_shell_delegate.cc

Index: chrome/browser/android/vr_shell/vr_shell_delegate.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell_delegate.cc b/chrome/browser/android/vr_shell/vr_shell_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..57088626926067a321d8210a2af6dc1cc5a6e843
--- /dev/null
+++ b/chrome/browser/android/vr_shell/vr_shell_delegate.cc
@@ -0,0 +1,78 @@
+// 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 <jni.h>
+
+#include "base/android/jni_android.h"
+#include "chrome/browser/android/vr_shell/vr_shell.h"
+#include "jni/VrShellDelegate_jni.h"
+
+using base::android::JavaParamRef;
+using base::android::AttachCurrentThread;
+
+namespace vr_shell {
+
+VrShellDelegate::VrShellDelegate(JNIEnv* env, jobject obj)
+    : device_provider_(nullptr) {
+  j_vr_shell_delegate_.Reset(env, obj);
+  GvrDelegateProvider::SetInstance(this);
+}
+
+VrShellDelegate::~VrShellDelegate() {
+  GvrDelegateProvider::SetInstance(nullptr);
+}
+
+// Returns true if the GvrDeviceProvider needs to handle shutdown first.
+bool VrShellDelegate::ExitVRIfNecessary(JNIEnv* env, jobject obj) {
+  if (!device_provider_)
+    return false;
+
+  device_provider_->OnGvrDelegateRemoved();
+  return true;
+}
+
+bool VrShellDelegate::RequestWebVRPresent(
+    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_enterWebVRIfNecessary(env,
+                                                    j_vr_shell_delegate_.obj());
+}
+
+void VrShellDelegate::ExitWebVRPresent() {
+  if (!device_provider_)
+    return;
+
+  device_provider_ = nullptr;
+
+  // VRShell is no longer needed by WebVR, allow it to shut down if it's not
+  // being used elsewhere.
+  JNIEnv* env = AttachCurrentThread();
+  Java_VrShellDelegate_exitWebVRIfNecessary(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