Experiment with more aggressive MSE GC on memory pressure

media/filters/source_buffer_stream.h

Index: media/filters/source_buffer_stream.h
diff --git a/media/filters/source_buffer_stream.h b/media/filters/source_buffer_stream.h
index 566477b81bd1120654d65221e9bd2885727aabd8..b88d2dc56709e3bc2762c4f78531610366031247 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -91,7 +91,8 @@ class MEDIA_EXPORT SourceBufferStream {
   // Frees up space if the SourceBufferStream is taking up too much memory.
   // |media_time| is current playback position.
   bool GarbageCollectIfNeeded(DecodeTimestamp media_time,
-                              size_t newDataSize);
+                              size_t eviction_size,
+                              size_t* bytes_released = nullptr);
 
   // Changes the SourceBufferStream's state so that it will start returning
   // buffers starting from the closest keyframe before |timestamp|.
@@ -153,6 +154,8 @@ class MEDIA_EXPORT SourceBufferStream {
   // yet.
   base::TimeDelta GetMaxInterbufferDistance() const;
 
+  size_t memory_limit() const { return memory_limit_; }
+
   void set_memory_limit(size_t memory_limit) {
     memory_limit_ = memory_limit;
   }