Switch AudioRendererSinkCache away from base::Bind

AudioRendererSinkCache::DeleteLaterIfUnused signature was
changed to take a scoped_refptr<> instead of raw pointer, which
is needed by WTF::UnretainedRef().

The TODO in WebAudioDeviceFactory::GetOutputDeviceInfo()
was also removed, given that other part of Blink use
base::ThreadPool::CreateSequencedTaskRunner(). The relevant aspect
is that the SequencedTaskRunner instance created operates iver
WTF::CrossThreadBind variants.

BUG=787252
R=guido@chromium.org

Change-Id: If8d7453874d13599280fbe9d3c6c2cb8fc5623c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2419373
Commit-Queue: Antonio Gomes (GMT-4) <tonikitoo@igalia.com>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813249}

third_party/blink/renderer/modules/media/audio/audio_renderer_sink_cache.cc

@@ -8,13 +8,11 @@
 #include <memory>
 #include <utility>
 
-#include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "base/synchronization/lock.h"
-#include "base/task/post_task.h"
 #include "base/trace_event/trace_event.h"
 #include "media/audio/audio_device_description.h"
 #include "media/base/audio_renderer_sink.h"
@@ -23,7 +21,9 @@
 #include "third_party/blink/renderer/core/execution_context/execution_context_lifecycle_observer.h"
 #include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
+#include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"
 #include "third_party/blink/renderer/platform/supplementable.h"
+#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"
 
 namespace blink {
 
@@ -245,14 +245,15 @@ void AudioRendererSinkCache::ReleaseSink(
 }
 
 void AudioRendererSinkCache::DeleteLaterIfUnused(
-    const media::AudioRendererSink* sink_ptr) {
-  cleanup_task_runner_->PostDelayedTask(
-      FROM_HERE,
-      base::BindOnce(&AudioRendererSinkCache::DeleteSink,
-                     // Unretained is safe here since this is a process-wide
-                     // singleton and tests will ensure lifetime.
-                     base::Unretained(this), base::RetainedRef(sink_ptr),
-                     false /*do not delete if used*/),
+    scoped_refptr<media::AudioRendererSink> sink) {
+  PostDelayedCrossThreadTask(
+      *cleanup_task_runner_, FROM_HERE,
+      CrossThreadBindOnce(
+          &AudioRendererSinkCache::DeleteSink,
+          // Unretained is safe here since this is a process-wide
+          // singleton and tests will ensure lifetime.
+          CrossThreadUnretained(this), WTF::RetainedRef(std::move(sink)),
+          false /*do not delete if used*/),
       delete_timeout_);
 }
 
@@ -343,7 +344,7 @@ void AudioRendererSinkCache::CacheOrStopUnusedSink(
     cache_.push_back(cache_entry);
   }
 
-  DeleteLaterIfUnused(cache_entry.sink.get());
+  DeleteLaterIfUnused(cache_entry.sink);
 }
 
 void AudioRendererSinkCache::DropSinksForFrame(

third_party/blink/renderer/modules/media/audio/audio_renderer_sink_cache.h

@@ -74,7 +74,7 @@ class MODULES_EXPORT AudioRendererSinkCache {
 
   // Schedules a sink for deletion. Deletion will be performed on the same
   // thread the cache is created on.
-  void DeleteLaterIfUnused(const media::AudioRendererSink* sink_ptr);
+  void DeleteLaterIfUnused(scoped_refptr<media::AudioRendererSink> sink);
 
   // Deletes a sink from the cache. If |force_delete_used| is set, a sink being
   // deleted can (and should) be in use at the moment of deletion; otherwise the

third_party/blink/renderer/modules/media/audio/web_audio_device_factory.cc

@@ -193,9 +193,6 @@ media::OutputDeviceInfo WebAudioDeviceFactory::GetOutputDeviceInfo(
       base::TimeDelta::FromMilliseconds(5000);
 
   // There's one process wide instance that lives on the render thread.
-  //
-  // TODO(crbug.com/787252): Replace the use of base::ThreadPool below by
-  // worker_pool::PostTask().
   static base::NoDestructor<AudioRendererSinkCache> cache(
       base::ThreadPool::CreateSequencedTaskRunner(
           {base::TaskPriority::BEST_EFFORT,