Support pausing media when a context is frozen.

Media is resumed when the context is unpaused. This feature will be used
for bfcache and pausing iframes feature policy.

BUG=907125

Change-Id: Ic3925ea1a4544242b7bf0b9ad8c9cb9f63976bbd
Reviewed-on: https://chromium-review.googlesource.com/c/1410126
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623319}
void BaseAudioContext::Initialize() {
  if (IsDestinationInitialized())
    return;

  FFTFrame::Initialize();

  audio_worklet_ = AudioWorklet::Create(this);

  if (destination_node_) {
    destination_node_->Handler().Initialize();
    destination_handler_ = &destination_node_->GetAudioDestinationHandler();

    listener_ = AudioListener::Create(*this);
  }
}

void BaseAudioContext::Initialize() {
  if (IsDestinationInitialized())
    return;

  FFTFrame::Initialize();

  audio_worklet_ = AudioWorklet::Create(this);

  if (destination_node_) {
    destination_node_->Handler().Initialize();
    destination_handler_ = &destination_node_->GetAudioDestinationHandler();

    listener_ = AudioListener::Create(*this);
  }
}
