Media track ID visibility at BWE level

webrtc/call/bitrate_allocator.h

Index: webrtc/call/bitrate_allocator.h
diff --git a/webrtc/call/bitrate_allocator.h b/webrtc/call/bitrate_allocator.h
index e92eac90e63b0db8e380b47c8168537f9c322d29..9348efa74305d3ff06a527686413e79b314311b2 100644
--- a/webrtc/call/bitrate_allocator.h
+++ b/webrtc/call/bitrate_allocator.h
@@ -16,6 +16,7 @@
 #include <map>
 #include <utility>
 #include <vector>
+#include <string>
 
 #include "webrtc/base/sequenced_task_checker.h"
 
@@ -82,7 +83,8 @@ class BitrateAllocator {
                    uint32_t min_bitrate_bps,
                    uint32_t max_bitrate_bps,
                    uint32_t pad_up_bitrate_bps,
-                   bool enforce_min_bitrate);
+                   bool enforce_min_bitrate,
+                   std::string track_id);
 
   // Removes a previously added observer, but will not trigger a new bitrate
   // allocation.
@@ -99,14 +101,16 @@ class BitrateAllocator {
                    uint32_t min_bitrate_bps,
                    uint32_t max_bitrate_bps,
                    uint32_t pad_up_bitrate_bps,
-                   bool enforce_min_bitrate)
+                   bool enforce_min_bitrate,
+                   std::string track_id)
         : observer(observer),
           min_bitrate_bps(min_bitrate_bps),
           max_bitrate_bps(max_bitrate_bps),
           pad_up_bitrate_bps(pad_up_bitrate_bps),
           enforce_min_bitrate(enforce_min_bitrate),
           allocated_bitrate_bps(-1),
-          media_ratio(1.0) {}
+          media_ratio(1.0),
+          track_id(track_id) {}
 
     BitrateAllocatorObserver* observer;
     uint32_t min_bitrate_bps;
@@ -115,6 +119,7 @@ class BitrateAllocator {
     bool enforce_min_bitrate;
     int64_t allocated_bitrate_bps;
     double media_ratio;  // Part of the total bitrate used for media [0.0, 1.0].
+    std::string track_id;

[nisse-webrtc, 2017/09/18 08:44:28]

Can it be const? (I guess all other members are expected to be updated during
the life of the object?)

[alexnarest, 2017/09/29 12:13:57]

Other members such as observer, min/max bitrate, etc. are not updated too but
ObserverConfigs holds values of ObserverConfig and copies them a lot.

   };
 
   // Calculates the minimum requested send bitrate and max padding bitrate and