Reimplemeted "Test and fix for huge bwe drop after alr state"

webrtc/modules/pacing/alr_detector.cc

Index: webrtc/modules/pacing/alr_detector.cc
diff --git a/webrtc/modules/pacing/alr_detector.cc b/webrtc/modules/pacing/alr_detector.cc
index 93752cf751395d99db60e146ef87f4b0558e4dcb..a262c6dcb102a5f27ee6bad4dd4fb6796583fec3 100644
--- a/webrtc/modules/pacing/alr_detector.cc
+++ b/webrtc/modules/pacing/alr_detector.cc
@@ -103,4 +103,21 @@ AlrDetector::ParseAlrSettingsFromFieldTrial() {
   return ret;
 }
 
+AlrState::AlrState() : was_in_alr_(false) {}
+
+void AlrState::Update(rtc::Optional<int64_t> alr_start_time_ms) {
+  if (was_in_alr_ && !alr_start_time_ms) {
+    alr_state_changed_to_.emplace(AlrState::State::kNotInAlr);
+  } else if (!was_in_alr_ && alr_start_time_ms) {
+    alr_state_changed_to_.emplace(AlrState::State::kInAlr);
+  } else {
+    alr_state_changed_to_.reset();

[philipel, 2017/07/14 13:56:23]

Isn't |alr_state_changed_to_| just |current_state_|.

[tschumi, 2017/07/14 15:36:51]

Removed AlrState

+  }
+  was_in_alr_ = alr_start_time_ms.has_value();

[philipel, 2017/07/14 13:56:23]

|was_in_alr_| same as |in_alr_|?

[tschumi, 2017/07/14 15:36:51]

Removed AlrState

+}
+
+bool AlrState::HasChangedTo(AlrState::State state) {
+  return alr_state_changed_to_ && *alr_state_changed_to_ == state;
+}
+
 }  // namespace webrtc