Moved ALR experiment settings to new experiments folder.

This replaces most of the existing dependencies on the application
limited region(ALR) detector. This is to achieve a greater separation of
concerns and will make further refactoring regarding the ALR Detector
less invasive on other parts of the code base.

Bug: webrtc:8415
Change-Id: I92912254c6d02285cce6a88f6789f0ac94794c88
Reviewed-on: https://webrtc-review.googlesource.com/37560
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21598}

rtc_base/experiments/alr_experiment.h

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2018 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.
+ */
+
+#ifndef RTC_BASE_EXPERIMENTS_ALR_EXPERIMENT_H_
+#define RTC_BASE_EXPERIMENTS_ALR_EXPERIMENT_H_
+
+#include "api/optional.h"
+
+namespace webrtc {
+struct AlrExperimentSettings {
+ public:
+  float pacing_factor;
+  int64_t max_paced_queue_time;
+  int alr_bandwidth_usage_percent;
+  int alr_start_budget_level_percent;
+  int alr_stop_budget_level_percent;
+  // Will be sent to the receive side for stats slicing.
+  // Can be 0..6, because it's sent as a 3 bits value and there's also
+  // reserved value to indicate absence of experiment.
+  int group_id;
+
+  static const char kScreenshareProbingBweExperimentName[];
+  static const char kStrictPacingAndProbingExperimentName[];
+  static rtc::Optional<AlrExperimentSettings> CreateFromFieldTrial(
+      const char* experiment_name);
+  static bool MaxOneFieldTrialEnabled();
+
+ private:
+  AlrExperimentSettings() = default;
+};
+}  // namespace webrtc
+
+#endif  // RTC_BASE_EXPERIMENTS_ALR_EXPERIMENT_H_