Add support for handling reordered SS data on the receive-side for VP9.

webrtc/modules/video_coding/main/source/jitter_buffer.h

Index: webrtc/modules/video_coding/main/source/jitter_buffer.h
diff --git a/webrtc/modules/video_coding/main/source/jitter_buffer.h b/webrtc/modules/video_coding/main/source/jitter_buffer.h
index 8a05f1ff178097b8dff7ab2a725045ef063d8da5..31e3be257824893e664499f7e651676ed8898e5f 100644
--- a/webrtc/modules/video_coding/main/source/jitter_buffer.h
+++ b/webrtc/modules/video_coding/main/source/jitter_buffer.h
@@ -74,6 +74,37 @@ class FrameList
   void Reset(UnorderedFrameList* free_frames);
 };
 
+class Vp9SsMap {
+ public:
+  typedef std::map<uint32_t, GofInfoVP9, TimestampLessThan> SsMap;
+  bool Insert(const VCMPacket& packet);
+  void Reset();
+
+  // Removes SS data that are older than |timestamp|.
+  // The |timestamp| should be an old timestamp, i.e. packets with older
+  // timestamps should no longer be inserted.
+  void RemoveOld(uint32_t timestamp);
+
+  bool UpdatePacket(VCMPacket* packet);
+  void UpdateFrames(FrameList* frames);
+
+  // Public for testing.
+  // Returns an iterator to the corresponding SS data for the input |timestamp|.
+  bool Find(uint32_t timestamp, SsMap::iterator* it);
+
+ private:
+  // These two functions are called by RemoveOld.
+  // Checks if it is time to do a clean up (done each kSsCleanupIntervalSec).
+  bool TimeForCleanup(uint32_t timestamp) const;
+
+  // Advances the oldest SS data to handle timestamp wrap in cases where SS data
+  // are received very seldom (e.g. only once in beginning, second when
+  // IsNewerTimestamp is not true).
+  void AdvanceFront(uint32_t timestamp);
+
+  SsMap ss_map_;
+};
+
 class VCMJitterBuffer {
  public:
   VCMJitterBuffer(Clock* clock, rtc::scoped_ptr<EventWrapper> event);
@@ -307,10 +338,8 @@ class VCMJitterBuffer {
   FrameList incomplete_frames_ GUARDED_BY(crit_sect_);
   VCMDecodingState last_decoded_state_ GUARDED_BY(crit_sect_);
   bool first_packet_since_reset_;
-  // Contains last received frame's temporal information for non-flexible mode.
-  GofInfoVP9 last_gof_;
-  uint32_t last_gof_timestamp_;
-  bool last_gof_valid_;
+  // Contains scalability structure data for VP9.
+  Vp9SsMap vp9_ss_map_ GUARDED_BY(crit_sect_);
 
   // Statistics.
   VCMReceiveStatisticsCallback* stats_callback_ GUARDED_BY(crit_sect_);