Experiment with more aggressive MSE GC on memory pressure

media/filters/chunk_demuxer.h

Index: media/filters/chunk_demuxer.h
diff --git a/media/filters/chunk_demuxer.h b/media/filters/chunk_demuxer.h
index 020aa1417e4198da25871326c37fee2511d2c9a7..53d0e874ecef49b3c10f8b05ca163c59be82b4be 100644
--- a/media/filters/chunk_demuxer.h
+++ b/media/filters/chunk_demuxer.h
@@ -16,6 +16,7 @@
 #include <vector>
 
 #include "base/macros.h"
+#include "base/memory/memory_pressure_listener.h"
 #include "base/synchronization/lock.h"
 #include "media/base/byte_queue.h"
 #include "media/base/demuxer.h"
@@ -60,11 +61,16 @@ class MEDIA_EXPORT ChunkDemuxerStream : public DemuxerStream {
   void Remove(base::TimeDelta start, base::TimeDelta end,
               base::TimeDelta duration);
 
-  // If the buffer is full, attempts to try to free up space, as specified in
-  // the "Coded Frame Eviction Algorithm" in the Media Source Extensions Spec.
+  // Runs the "Coded Frame Eviction Algorithm" from the Media Source Extensions
+  // spec: https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  // |eviction_size| is an input parameter specifying how much space we want to
+  // be available in the buffer after eviction.
+  // |bytes_released| is an optional output parameter, if non-null it will
+  // indicate how much buffer space was actually released.
   // Returns false iff buffer is still full after running eviction.
-  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
-  bool EvictCodedFrames(DecodeTimestamp media_time, size_t newDataSize);
+  bool EvictCodedFrames(DecodeTimestamp media_time,
+                        size_t eviction_size,
+                        size_t* bytes_released = nullptr);
 
   // Signal to the stream that duration has changed to |duration|.
   void OnSetDuration(base::TimeDelta duration);
@@ -118,6 +124,7 @@ class MEDIA_EXPORT ChunkDemuxerStream : public DemuxerStream {
 
   // Sets the memory limit, in bytes, on the SourceBufferStream.
   void SetStreamMemoryLimit(size_t memory_limit);
+  size_t stream_memory_limit() const;
 
   bool supports_partial_append_window_trimming() const {
     return partial_append_window_trimming_enabled_;
@@ -262,13 +269,20 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   void Remove(const std::string& id, base::TimeDelta start,
               base::TimeDelta end);
 
-  // If the buffer is full, attempts to try to free up space, as specified in
-  // the "Coded Frame Eviction Algorithm" in the Media Source Extensions Spec.
+  // Runs the "Coded Frame Eviction Algorithm" from the Media Source Extensions
+  // spec: https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  // |eviction_size| is an input parameter specifying how much space we want to
+  // be available in the buffer after eviction.
+  // |bytes_released| is an optional output parameter, if non-null it will

[wolenetz, 2017/01/12 22:21:49]

Where is this param decl'ed?

[servolk, 2017/01/12 22:58:41]

Oops, I've copy/pasted this comment from ChunkDemuxerStream::EvictCodedFrames,
where I've added the optional bytes_released parameter. I'll remove it here.

+  // indicate how much buffer space was actually released.
   // Returns false iff buffer is still full after running eviction.
-  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
   bool EvictCodedFrames(const std::string& id,
                         base::TimeDelta currentMediaTime,
-                        size_t newDataSize);
+                        size_t eviction_size);
+
+  void OnMemoryPressure(
+      base::TimeDelta currentMediaTime,
+      base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
   // Returns the current presentation duration.
   double GetDuration();