Experiment with more aggressive MSE GC on memory pressure

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index c6b8b571cea6a261dc31fc9e629025bf7185660a..f130ce7548a3699c5a9d2c13dbb99335c5f5998e 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -18,6 +18,7 @@
 #include "base/debug/alias.h"
 #include "base/debug/crash_logging.h"
 #include "base/location.h"
+#include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
@@ -1109,6 +1110,21 @@ void WebMediaPlayerImpl::OnDemuxerOpened() {
       new WebMediaSourceImpl(chunk_demuxer_, media_log_));
 }
 
+void WebMediaPlayerImpl::OnMemoryPressure(
+    base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
+  DVLOG(2) << __func__ << " memory_pressure_level=" << memory_pressure_level;
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  if (chunk_demuxer_) {
+    // base::Unretained is safe, since chunk_demuxer_ is actually owned by
+    // |this| via this->demuxer_.
+    media_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&ChunkDemuxer::OnMemoryPressure,
+                              base::Unretained(chunk_demuxer_),
+                              base::TimeDelta::FromSecondsD(currentTime()),
+                              memory_pressure_level));
+  }
+}
+
 void WebMediaPlayerImpl::OnError(PipelineStatus status) {
   DVLOG(1) << __func__;
   DCHECK(main_task_runner_->BelongsToCurrentThread());
@@ -1650,6 +1666,11 @@ void WebMediaPlayerImpl::StartPipeline() {
   // TODO(sandersd): On Android, defer Start() if the tab is not visible.
   seeking_ = true;
   pipeline_controller_.Start(demuxer_.get(), this, is_streaming, is_static);
+
+  // base::Unretained is safe because |this| owns memory_pressure_listener_.
+  memory_pressure_listener_ =
+      base::MakeUnique<base::MemoryPressureListener>(base::Bind(
+          &WebMediaPlayerImpl::OnMemoryPressure, base::Unretained(this)));
 }
 
 void WebMediaPlayerImpl::SetNetworkState(WebMediaPlayer::NetworkState state) {