Cast: Fix two video freezing problems

media/cast/transport/rtp_sender/packet_storage/packet_storage.h

Index: media/cast/transport/rtp_sender/packet_storage/packet_storage.h
diff --git a/media/cast/transport/rtp_sender/packet_storage/packet_storage.h b/media/cast/transport/rtp_sender/packet_storage/packet_storage.h
index b5981e858463e34a22dc40e971b250bdb6020268..85efc664c48b96f7574d22c456a9c8397651df78 100644
--- a/media/cast/transport/rtp_sender/packet_storage/packet_storage.h
+++ b/media/cast/transport/rtp_sender/packet_storage/packet_storage.h
@@ -23,16 +23,25 @@ namespace cast {
 namespace transport {
 
 class StoredPacket;
-typedef std::map<uint32, std::pair<PacketKey, PacketRef> > PacketMap;
-typedef std::multimap<base::TimeTicks, uint32> TimeToPacketMap;
+
+// StorageIndex contains {frame_id, packet_id}.
+typedef std::pair<uint32, uint16> StorageIndex;
+typedef std::map<StorageIndex, std::pair<PacketKey, PacketRef> > PacketMap;
+
+// Frame IDs are generally stored as 8-bit values when sent over the
+// wire. This means that having a history longer than 255 frames makes
+// no sense.
+const int kMaxStoredFrames = 255;
 
 class PacketStorage {
  public:
-  static const unsigned int kMaxStoredPackets = 1000;
-
-  PacketStorage(base::TickClock* clock, int max_time_stored_ms);
+  PacketStorage(int stored_frames);
   virtual ~PacketStorage();
 
+  // Returns true if this class is configured correctly.
+  // (stored frames > 0 && stored_frames < kMaxStoredFrames)
+  bool IsValid() const;
+
   void StorePacket(uint32 frame_id,
                    uint16 packet_id,
                    const PacketKey& key,
@@ -44,15 +53,20 @@ class PacketStorage {
       SendPacketVector* packets_to_resend);
 
   // Copies packet into the packet list.
-  bool GetPacket(uint8 frame_id, uint16 packet_id, SendPacketVector* packets);
-
+  bool GetPacket(uint8 frame_id_8bit,
+                 uint16 packet_id,
+                 SendPacketVector* packets);
  private:
-  void CleanupOldPackets(base::TimeTicks now);
+  FRIEND_TEST_ALL_PREFIXES(PacketStorageTest, PacketContent);
+
+  // Same as GetPacket, but takes a 32-bit frame id.
+  bool GetPacket32(uint32 frame_id,
+                   uint16 packet_id,
+                   SendPacketVector* packets);
+  void CleanupOldPackets(uint32 current_frame_id);
 
-  base::TickClock* const clock_;  // Not owned by this class.
-  base::TimeDelta max_time_stored_;
   PacketMap stored_packets_;
-  TimeToPacketMap time_to_packet_map_;
+  int stored_frames_;
 
   DISALLOW_COPY_AND_ASSIGN(PacketStorage);
 };