Simplify BitrateAllocator::AddBitrateObserver.

webrtc/modules/bitrate_controller/include/bitrate_allocator.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  *
  *  Usage: this class will register multiple RtcpBitrateObserver's one at each
@@ skipping 19 matching lines @@
 class BitrateAllocator {
  public:
   BitrateAllocator();
 
   void OnNetworkChanged(uint32_t target_bitrate,
                         uint8_t fraction_loss,
                         int64_t rtt);
 
   // Set the start and max send bitrate used by the bandwidth management.
   //
-  // observer, updates bitrates if already in use.
-  // min_bitrate_bps = 0 equals no min bitrate.
-  // max_bitrate_bps = 0 equals no max bitrate.
-  // TODO(holmer): Remove start_bitrate_bps when old API is gone.
+  // |observer| updates bitrates if already in use.
+  // |min_bitrate_bps| = 0 equals no min bitrate.
+  // |max_bitrate_bps| = 0 equals no max bitrate.
+  // Returns bitrate allocated for the bitrate observer.
   int AddBitrateObserver(BitrateObserver* observer,
-                         uint32_t start_bitrate_bps,
                          uint32_t min_bitrate_bps,
-                         uint32_t max_bitrate_bps,
-                         int* new_observer_bitrate_bps);
+                         uint32_t max_bitrate_bps);
 
   void RemoveBitrateObserver(BitrateObserver* observer);
 
   void GetMinMaxBitrateSumBps(int* min_bitrate_sum_bps,
                               int* max_bitrate_sum_bps) const;
 
   // This method controls the behavior when the available bitrate is lower than
   // the minimum bitrate, or the sum of minimum bitrates.
   // When true, the bitrate will never be set lower than the minimum bitrate(s).
   // When false, the bitrate observers will be allocated rates up to their
   // respective minimum bitrate, satisfying one observer after the other.
   void EnforceMinBitrate(bool enforce_min_bitrate);
 
  private:
   struct BitrateConfiguration {
-    BitrateConfiguration(uint32_t start_bitrate,
-                         uint32_t min_bitrate,
-                         uint32_t max_bitrate)
-        : start_bitrate_(start_bitrate),
-          min_bitrate_(min_bitrate),
-          max_bitrate_(max_bitrate) {}
-    uint32_t start_bitrate_;
-    uint32_t min_bitrate_;
-    uint32_t max_bitrate_;
+    BitrateConfiguration(uint32_t min_bitrate, uint32_t max_bitrate)
+        : min_bitrate(min_bitrate), max_bitrate(max_bitrate) {}
+    uint32_t min_bitrate;
+    uint32_t max_bitrate;
   };
   struct ObserverConfiguration {
     ObserverConfiguration(BitrateObserver* observer, uint32_t bitrate)
-        : observer_(observer), min_bitrate_(bitrate) {}
-    BitrateObserver* observer_;
-    uint32_t min_bitrate_;
+        : observer(observer), min_bitrate(bitrate) {}
+    BitrateObserver* const observer;
+    uint32_t min_bitrate;
   };
   typedef std::pair<BitrateObserver*, BitrateConfiguration>
       BitrateObserverConfiguration;
   typedef std::list<BitrateObserverConfiguration> BitrateObserverConfList;
   typedef std::multimap<uint32_t, ObserverConfiguration> ObserverSortingMap;
   typedef std::map<BitrateObserver*, int> ObserverBitrateMap;
 
   BitrateObserverConfList::iterator FindObserverConfigurationPair(
       const BitrateObserver* observer) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
   ObserverBitrateMap AllocateBitrates() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
   ObserverBitrateMap NormalRateAllocation(uint32_t bitrate,
                                           uint32_t sum_min_bitrates)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
   ObserverBitrateMap LowRateAllocation(uint32_t bitrate)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
   rtc::scoped_ptr<CriticalSectionWrapper> crit_sect_;
   // Stored in a list to keep track of the insertion order.
   BitrateObserverConfList bitrate_observers_ GUARDED_BY(crit_sect_);
   bool bitrate_observers_modified_ GUARDED_BY(crit_sect_);
   bool enforce_min_bitrate_ GUARDED_BY(crit_sect_);
   uint32_t last_bitrate_bps_ GUARDED_BY(crit_sect_);
   uint8_t last_fraction_loss_ GUARDED_BY(crit_sect_);
   int64_t last_rtt_ GUARDED_BY(crit_sect_);
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_ALLOCATOR_H_