Allow pacer to boost bitrate in order to meet time constraints.

webrtc/modules/pacing/paced_sender_unittest.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 646 matching lines @@
     if (time_until_process <= 0) {
       send_bucket_->Process();
     } else {
       clock_.AdvanceTimeMilliseconds(time_until_process);
     }
   }
   int64_t duration = clock_.TimeInMilliseconds() - time_start;
 
   EXPECT_EQ(0, send_bucket_->ExpectedQueueTimeMs());
 
-  // Allow for aliasing, duration should be in [expected(n - 1), expected(n)].
-  EXPECT_LE(duration, queue_in_ms);
-  EXPECT_GE(duration,
-            queue_in_ms - static_cast<int64_t>(kPacketSize * 8 / kMaxBitrate));
+  // Allow for aliasing, duration should be within one pack of max time limit.
+  EXPECT_LE(duration, PacedSender::kMaxQueueLengthMs);
+  EXPECT_GE(duration, PacedSender::kMaxQueueLengthMs -
+                          static_cast<int64_t>(kPacketSize * 8 / kMaxBitrate));

[stefan-webrtc, 2015/10/28 15:45:23]

EXPECT_NEAR(duration, PacedSender::.., kPacketSize*8 / kMaxBitrate);

[sprang_webrtc, 2015/11/02 12:17:56]

Done.

 }
 
 TEST_F(PacedSenderTest, QueueTimeGrowsOverTime) {
   uint32_t ssrc = 12346;
   uint16_t sequence_number = 1234;
   EXPECT_EQ(0, send_bucket_->QueueInMs());
 
   send_bucket_->UpdateBitrate(30, kPaceMultiplier * 30, 0);
   SendAndExpectPacket(PacedSender::kNormalPriority,
                       ssrc,
@@ skipping 144 matching lines @@
                              sequence_number++, clock_.TimeInMilliseconds(),
                              kPacketSize, false);
 
   // Don't send padding if queue is non-empty, even if padding budget > 0.
   EXPECT_CALL(callback_, TimeToSendPadding(_)).Times(0);
   send_bucket_->Process();
 }
 
 }  // namespace test
 }  // namespace webrtc