Expose VSync pausing through WindowAndroid and pause VSync during webVR presentation

ui/android/window_android.cc

 // Copyright 2013 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 "ui/android/window_android.h"
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
@@ skipping 14 matching lines @@
 using base::android::JavaRef;
 using base::android::ScopedJavaLocalRef;
 
 class WindowAndroid::WindowBeginFrameSource : public cc::BeginFrameSource {
  public:
   explicit WindowBeginFrameSource(WindowAndroid* window)
       : window_(window),
         observers_(
             base::ObserverList<cc::BeginFrameObserver>::NOTIFY_EXISTING_ONLY),
         observer_count_(0),
-        next_sequence_number_(cc::BeginFrameArgs::kStartingFrameNumber) {}
+        next_sequence_number_(cc::BeginFrameArgs::kStartingFrameNumber),
+        paused_(false) {}
   ~WindowBeginFrameSource() override {}
 
   // cc::BeginFrameSource implementation.
   void AddObserver(cc::BeginFrameObserver* obs) override;
   void RemoveObserver(cc::BeginFrameObserver* obs) override;
   void DidFinishFrame(cc::BeginFrameObserver* obs,
                       const cc::BeginFrameAck& ack) override {}
   bool IsThrottled() const override { return true; }
 
   void OnVSync(base::TimeTicks frame_time, base::TimeDelta vsync_period);
+  void OnPauseChanged(bool paused);
 
  private:
   WindowAndroid* const window_;
   base::ObserverList<cc::BeginFrameObserver> observers_;
   int observer_count_;
   cc::BeginFrameArgs last_begin_frame_args_;
   uint64_t next_sequence_number_;
+  bool paused_;
 };
 
 void WindowAndroid::WindowBeginFrameSource::AddObserver(
     cc::BeginFrameObserver* obs) {
   DCHECK(obs);
   DCHECK(!observers_.HasObserver(obs));
 
   observers_.AddObserver(obs);
   observer_count_++;
-  obs->OnBeginFrameSourcePausedChanged(false);
+  obs->OnBeginFrameSourcePausedChanged(paused_);
   window_->SetNeedsBeginFrames(true);
 
   // Send a MISSED BeginFrame if possible and necessary.
   if (last_begin_frame_args_.IsValid()) {
     cc::BeginFrameArgs last_args = obs->LastUsedBeginFrameArgs();
     if (!last_args.IsValid() ||
         last_args.frame_time < last_begin_frame_args_.frame_time) {
       DCHECK(last_args.sequence_number <
                  last_begin_frame_args_.sequence_number ||
              last_args.source_id != last_begin_frame_args_.source_id);
@@ skipping 28 matching lines @@
   last_begin_frame_args_ = cc::BeginFrameArgs::Create(
       BEGINFRAME_FROM_HERE, source_id(), next_sequence_number_, frame_time,
       deadline, vsync_period, cc::BeginFrameArgs::NORMAL);
   DCHECK(last_begin_frame_args_.IsValid());
   next_sequence_number_++;
 
   for (auto& obs : observers_)
     obs.OnBeginFrame(last_begin_frame_args_);
 }
 
+void WindowAndroid::WindowBeginFrameSource::OnPauseChanged(bool paused) {
+  paused_ = paused;
+  for (auto& obs : observers_)
+    obs.OnBeginFrameSourcePausedChanged(paused_);
+}
+
 WindowAndroid::WindowAndroid(JNIEnv* env, jobject obj, int display_id)
     : display_id_(display_id),
       compositor_(NULL),
       begin_frame_source_(new WindowBeginFrameSource(this)),
       needs_begin_frames_(false) {
   java_window_.Reset(env, obj);
 }
 
 void WindowAndroid::Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   delete this;
@@ skipping 116 matching lines @@
   for (WindowAndroidObserver& observer : observer_list_)
     observer.OnActivityStopped();
 }
 
 void WindowAndroid::OnActivityStarted(JNIEnv* env,
                                       const JavaParamRef<jobject>& obj) {
   for (WindowAndroidObserver& observer : observer_list_)
     observer.OnActivityStarted();
 }
 
+void WindowAndroid::SetVSyncPaused(JNIEnv* env,
+                                   const JavaParamRef<jobject>& obj,
+                                   bool paused) {
+  begin_frame_source_->OnPauseChanged(paused);
+}
+
 bool WindowAndroid::HasPermission(const std::string& permission) {
   JNIEnv* env = AttachCurrentThread();
   return Java_WindowAndroid_hasPermission(
       env, GetJavaObject(),
       base::android::ConvertUTF8ToJavaString(env, permission));
 }
 
 bool WindowAndroid::CanRequestPermission(const std::string& permission) {
   JNIEnv* env = AttachCurrentThread();
   return Java_WindowAndroid_canRequestPermission(
       env, GetJavaObject(),
       base::android::ConvertUTF8ToJavaString(env, permission));
 }
 
 WindowAndroid* WindowAndroid::GetWindowAndroid() const {
   DCHECK(parent_ == nullptr);
   return const_cast<WindowAndroid*>(this);
 }
 
 // ----------------------------------------------------------------------------
 // Native JNI methods
 // ----------------------------------------------------------------------------
 
 jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj, int sdk_display_id) {
   WindowAndroid* window = new WindowAndroid(env, obj, sdk_display_id);
   return reinterpret_cast<intptr_t>(window);
 }
 
 }  // namespace ui