BWE allocation strategy

This is reland of https://webrtc-review.googlesource.com/c/src/+/4860 with the fixed RampUpTest test

Bug: webrtc:8243
Change-Id: I4b90a449b00dd05feee974001e08fb40710b59ac
Reviewed-on: https://webrtc-review.googlesource.com/13124
Commit-Queue: Alex Narest <alexnarest@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20345}
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCBitrateAllocationStrategy.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCBitrateAllocationStrategy.mm
new file mode 100644
index 0000000..bc99767
--- /dev/null
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCBitrateAllocationStrategy.mm
@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2017 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.
+ */
+
+#import "WebRTC/RTCBitrateAllocationStrategy.h"
+
+#include "rtc_base/bitrateallocationstrategy.h"
+#include "rtc_base/checks.h"
+
+@implementation RTCBitrateAllocationStrategy
+
+@synthesize strategy = _strategy;
+
+- (instancetype)initWith:(rtc::BitrateAllocationStrategy*)strategy {
+  RTC_DCHECK(strategy);
+  if (self = [super init]) {
+    _strategy = strategy;
+  }
+  return self;
+}
+
+@end