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diff --git a/webrtc/call/bitrate_allocator.h b/webrtc/call/bitrate_allocator.h
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+/*
+ *  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
+ *  RTCP module. It will aggregate the results and run one bandwidth estimation
+ *  and push the result to the encoders via BitrateObserver(s).
+ */
+
+#ifndef WEBRTC_CALL_BITRATE_ALLOCATOR_H_
+#define WEBRTC_CALL_BITRATE_ALLOCATOR_H_
+
+#include <list>
+#include <map>
+#include <utility>
+
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread_annotations.h"
+#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
+
+namespace webrtc {
+
+class BitrateObserver;
+
+class BitrateAllocator {
+ public:
+  BitrateAllocator();
+
+  // Allocate target_bitrate across the registered BitrateObservers.
+  // Returns actual bitrate allocated (might be higher than target_bitrate if
+  // for instance EnforceMinBitrate() is enabled.
+  uint32_t 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.
+  // Returns bitrate allocated for the bitrate observer.
+  int AddBitrateObserver(BitrateObserver* observer,
+                         uint32_t min_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 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* 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_CALL_BITRATE_ALLOCATOR_H_