Use per-frame task runners at BaseAudioContext

This is a follow-up CL for https://chromium-review.googlesource.com/c/chromium/src/+/1229739

Bug: 870606
Change-Id: I0b877b3b611e9696e9d8fe38c8091ec8fbe5b304
Reviewed-on: https://chromium-review.googlesource.com/1233102Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hongchan Choi <hongchan@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592697}

third_party/blink/renderer/modules/webaudio/base_audio_context.cc

@@ -100,13 +100,15 @@ BaseAudioContext::BaseAudioContext(Document* document,
       is_cleared_(false),
       is_resolving_resume_promises_(false),
       has_posted_cleanup_task_(false),
-      deferred_task_handler_(DeferredTaskHandler::Create()),
+      deferred_task_handler_(DeferredTaskHandler::Create(
+          document->GetTaskRunner(TaskType::kInternalMedia))),
       context_state_(kSuspended),
       periodic_wave_sine_(nullptr),
       periodic_wave_square_(nullptr),
       periodic_wave_sawtooth_(nullptr),
       periodic_wave_triangle_(nullptr),
-      output_position_() {}
+      output_position_(),
+      task_runner_(document->GetTaskRunner(TaskType::kInternalMedia)) {}
 
 BaseAudioContext::~BaseAudioContext() {
   {
@@ -760,12 +762,12 @@ void BaseAudioContext::HandlePostRenderTasks(const AudioBus* destination_bus) {
         was_audible_ = is_audible;
         if (is_audible) {
           PostCrossThreadTask(
-              *Platform::Current()->MainThread()->GetTaskRunner(), FROM_HERE,
+              *task_runner_, FROM_HERE,
               CrossThreadBind(&BaseAudioContext::NotifyAudibleAudioStarted,
                               WrapCrossThreadPersistent(this)));
         } else {
           PostCrossThreadTask(
-              *Platform::Current()->MainThread()->GetTaskRunner(), FROM_HERE,
+              *task_runner_, FROM_HERE,
               CrossThreadBind(&BaseAudioContext::NotifyAudibleAudioStopped,
                               WrapCrossThreadPersistent(this)));
         }
@@ -848,7 +850,7 @@ void BaseAudioContext::ScheduleMainThreadCleanup() {
   if (has_posted_cleanup_task_)
     return;
   PostCrossThreadTask(
-      *Platform::Current()->MainThread()->GetTaskRunner(), FROM_HERE,
+      *task_runner_, FROM_HERE,
       CrossThreadBind(&BaseAudioContext::PerformCleanupOnMainThread,
                       WrapCrossThreadPersistent(this)));
   has_posted_cleanup_task_ = true;

third_party/blink/renderer/modules/webaudio/base_audio_context.h

@@ -49,6 +49,10 @@
 #include "third_party/blink/renderer/platform/wtf/threading.h"
 #include "third_party/blink/renderer/platform/wtf/vector.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace blink {
 
 class AnalyserNode;
@@ -466,6 +470,8 @@ class MODULES_EXPORT BaseAudioContext
   // determine audibility on render quantum boundaries, so counting quanta is
   // all that's needed.
   size_t total_audible_renders_ = 0;
+
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 };
 
 }  // namespace blink

third_party/blink/renderer/modules/webaudio/deferred_task_handler.cc

@@ -261,11 +261,15 @@ void DeferredTaskHandler::UpdateChangedChannelInterpretation() {
   deferred_channel_interpretation_change_.clear();
 }
 
-DeferredTaskHandler::DeferredTaskHandler()
-    : automatic_pull_nodes_need_updating_(false), audio_thread_(0) {}
+DeferredTaskHandler::DeferredTaskHandler(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    : automatic_pull_nodes_need_updating_(false),
+      task_runner_(std::move(task_runner)),
+      audio_thread_(0) {}
 
-scoped_refptr<DeferredTaskHandler> DeferredTaskHandler::Create() {
-  return base::AdoptRef(new DeferredTaskHandler());
+scoped_refptr<DeferredTaskHandler> DeferredTaskHandler::Create(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
+  return base::AdoptRef(new DeferredTaskHandler(std::move(task_runner)));
 }
 
 DeferredTaskHandler::~DeferredTaskHandler() {
@@ -319,7 +323,7 @@ void DeferredTaskHandler::RequestToDeleteHandlersOnMainThread() {
   deletable_orphan_handlers_.AppendVector(rendering_orphan_handlers_);
   rendering_orphan_handlers_.clear();
   PostCrossThreadTask(
-      *Platform::Current()->MainThread()->GetTaskRunner(), FROM_HERE,
+      *task_runner_, FROM_HERE,
       CrossThreadBind(&DeferredTaskHandler::DeleteHandlersOnMainThread,
                       scoped_refptr<DeferredTaskHandler>(this)));
 }

third_party/blink/renderer/modules/webaudio/deferred_task_handler.h

@@ -35,6 +35,10 @@
 #include "third_party/blink/renderer/platform/wtf/threading_primitives.h"
 #include "third_party/blink/renderer/platform/wtf/vector.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace blink {
 
 class BaseAudioContext;
@@ -59,7 +63,8 @@ class AudioSummingJunction;
 class MODULES_EXPORT DeferredTaskHandler final
     : public ThreadSafeRefCounted<DeferredTaskHandler> {
  public:
-  static scoped_refptr<DeferredTaskHandler> Create();
+  static scoped_refptr<DeferredTaskHandler> Create(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   ~DeferredTaskHandler();
 
   void HandleDeferredTasks();
@@ -180,7 +185,7 @@ class MODULES_EXPORT DeferredTaskHandler final
   };
 
  private:
-  DeferredTaskHandler();
+  explicit DeferredTaskHandler(scoped_refptr<base::SingleThreadTaskRunner>);
   void UpdateAutomaticPullNodes();
   void UpdateChangedChannelCountMode();
   void UpdateChangedChannelInterpretation();
@@ -227,6 +232,8 @@ class MODULES_EXPORT DeferredTaskHandler final
   // main thread will disable the outputs.
   Vector<scoped_refptr<AudioHandler>> finished_tail_processing_handlers_;
 
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
   // Graph locking.
   RecursiveMutex context_graph_mutex_;
   volatile ThreadIdentifier audio_thread_;