Remove SendPacer from ViEEncoder and make sure SendPacer starts at a valid bitrate

This reverts commit e30c27205148b34ba421184efe65f6a0780b436d (https://codereview.webrtc.org/1958053002/)

Original reverted cl is in patch set #1.
Changes in following patch sets.

The cl now also make sure SendPacer starts with the configured bitrate provided in a call to CongestionController::SetBweBitrates)()

It turns out that the failing tests in 609816 is due to a bug in the current code that runs the proper at 300kbit regardless of configured start bitrate.

Original cl description:
Remove SendPacer from ViEEncoder
This CL moves the logic where the ViEEncoder pause if the pacer is full to the BitrateController. If the queue is full, the controller reports a bitrate of zero to  Call (and BitrateAllocator)

BUG=chromium:609816, webrtc:5687
TBR=mflodman@webrtc.org
NOTRY=True  // Due to bug  in android_x86 cq builder....

Review-Url: https://codereview.webrtc.org/1958113003
Cr-Commit-Position: refs/heads/master@{#12688}
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
index 3c0d37c..09652d8 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
@@ -83,6 +83,10 @@
   return new BitrateControllerImpl(clock, observer);
 }
 
+BitrateController* BitrateController::CreateBitrateController(Clock* clock) {
+  return new BitrateControllerImpl(clock, nullptr);
+}
+
 BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
                                              BitrateObserver* observer)
     : clock_(clock),
@@ -94,8 +98,8 @@
       last_fraction_loss_(0),
       last_rtt_ms_(0),
       last_reserved_bitrate_bps_(0) {
-  // This calls the observer_, which means that the observer provided by the
-  // user must be ready to accept a bitrate update when it constructs the
+  // This calls the observer_ if set, which means that the observer provided by
+  // the user must be ready to accept a bitrate update when it constructs the
   // controller. We do this to avoid having to keep synchronized initial values
   // in both the controller and the allocator.
   MaybeTriggerOnNetworkChanged();
@@ -199,11 +203,15 @@
 }
 
 void BitrateControllerImpl::MaybeTriggerOnNetworkChanged() {
-  uint32_t bitrate;
+  if (!observer_)
+    return;
+
+  uint32_t bitrate_bps;
   uint8_t fraction_loss;
   int64_t rtt;
-  if (GetNetworkParameters(&bitrate, &fraction_loss, &rtt))
-    observer_->OnNetworkChanged(bitrate, fraction_loss, rtt);
+
+  if (GetNetworkParameters(&bitrate_bps, &fraction_loss, &rtt))
+    observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
 }
 
 bool BitrateControllerImpl::GetNetworkParameters(uint32_t* bitrate,
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
index a966121..5a61379 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
@@ -28,6 +28,8 @@
 
 class BitrateControllerImpl : public BitrateController {
  public:
+  // TODO(perkj): BitrateObserver has been deprecated and is not used in WebRTC.
+  // |observer| is left for project that is not yet updated.
   BitrateControllerImpl(Clock* clock, BitrateObserver* observer);
   virtual ~BitrateControllerImpl() {}
 
@@ -50,6 +52,11 @@
 
   void SetEventLog(RtcEventLog* event_log) override;
 
+  // Returns true if the parameters have changed since the last call.
+  bool GetNetworkParameters(uint32_t* bitrate,
+                            uint8_t* fraction_loss,
+                            int64_t* rtt) override;
+
   int64_t TimeUntilNextProcess() override;
   void Process() override;
 
@@ -64,20 +71,16 @@
                                     int number_of_packets,
                                     int64_t now_ms);
 
+  // Deprecated
   void MaybeTriggerOnNetworkChanged();
 
-  // Returns true if the parameters have changed since the last call.
-  bool GetNetworkParameters(uint32_t* bitrate,
-                            uint8_t* fraction_loss,
-                            int64_t* rtt);
-
   void OnNetworkChanged(uint32_t bitrate,
                         uint8_t fraction_loss,  // 0 - 255.
                         int64_t rtt) EXCLUSIVE_LOCKS_REQUIRED(critsect_);
 
   // Used by process thread.
-  Clock* clock_;
-  BitrateObserver* observer_;
+  Clock* const clock_;
+  BitrateObserver* const observer_;
   int64_t last_bitrate_update_ms_;
 
   rtc::CriticalSection critsect_;
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
index 3f467ef..4f92a38 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
@@ -14,11 +14,16 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
+#include "webrtc/modules/pacing/mock/mock_paced_sender.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
-using webrtc::RtcpBandwidthObserver;
-using webrtc::BitrateObserver;
+using ::testing::Exactly;
+using ::testing::Return;
+
 using webrtc::BitrateController;
+using webrtc::BitrateObserver;
+using webrtc::PacedSender;
+using webrtc::RtcpBandwidthObserver;
 
 uint8_t WeightedLoss(int num_packets1, uint8_t fraction_loss1,
                      int num_packets2, uint8_t fraction_loss2) {
diff --git a/webrtc/modules/bitrate_controller/include/bitrate_controller.h b/webrtc/modules/bitrate_controller/include/bitrate_controller.h
index d6cbc02..a61cf6a 100644
--- a/webrtc/modules/bitrate_controller/include/bitrate_controller.h
+++ b/webrtc/modules/bitrate_controller/include/bitrate_controller.h
@@ -18,6 +18,7 @@
 #include <map>
 
 #include "webrtc/modules/include/module.h"
+#include "webrtc/modules/pacing/paced_sender.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
 namespace webrtc {
@@ -26,6 +27,8 @@
 class RtcEventLog;
 struct PacketInfo;
 
+// Deprecated
+// TODO(perkj): Remove BitrateObserver when no implementations use it.
 class BitrateObserver {
   // Observer class for bitrate changes announced due to change in bandwidth
   // estimate or due to bitrate allocation changes. Fraction loss and rtt is
@@ -46,10 +49,15 @@
   // estimation and divide the available bitrate between all its registered
   // BitrateObservers.
  public:
-  static const int kDefaultStartBitrateKbps = 300;
+  static const int kDefaultStartBitratebps = 300000;
 
+  // Deprecated:
+  // TODO(perkj): BitrateObserver has been deprecated and is not used in WebRTC.
+  // Remove this method once other other projects does not use it.
   static BitrateController* CreateBitrateController(Clock* clock,
                                                     BitrateObserver* observer);
+  static BitrateController* CreateBitrateController(Clock* clock);
+
   virtual ~BitrateController() {}
 
   virtual RtcpBandwidthObserver* CreateRtcpBandwidthObserver() = 0;
@@ -71,6 +79,10 @@
   virtual bool AvailableBandwidth(uint32_t* bandwidth) const = 0;
 
   virtual void SetReservedBitrate(uint32_t reserved_bitrate_bps) = 0;
+
+  virtual bool GetNetworkParameters(uint32_t* bitrate,
+                                    uint8_t* fraction_loss,
+                                    int64_t* rtt) = 0;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
diff --git a/webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h b/webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h
index 5290b01..da6169e 100644
--- a/webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h
+++ b/webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h
@@ -39,6 +39,8 @@
   MOCK_METHOD1(SetEventLog, void(RtcEventLog* event_log));
   MOCK_CONST_METHOD1(AvailableBandwidth, bool(uint32_t* bandwidth));
   MOCK_METHOD1(SetReservedBitrate, void(uint32_t reserved_bitrate_bps));
+  MOCK_METHOD3(GetNetworkParameters,
+               bool(uint32_t* bitrate, uint8_t* fraction_loss, int64_t* rtt));
 
   MOCK_METHOD0(Process, void());
   MOCK_METHOD0(TimeUntilNextProcess, int64_t());