Update RateStatistics to handle too-little-data case.

webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time_unittest.cc

 /*
  *  Copyright (c) 2013 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 17 matching lines @@
 
 TEST_F(RemoteBitrateEstimatorAbsSendTimeTest, InitialBehavior) {
   InitialBehaviorTestHelper(674840);
 }
 
 TEST_F(RemoteBitrateEstimatorAbsSendTimeTest, RateIncreaseReordering) {
   RateIncreaseReorderingTestHelper(674840);
 }
 
 TEST_F(RemoteBitrateEstimatorAbsSendTimeTest, RateIncreaseRtpTimestamps) {
-  RateIncreaseRtpTimestampsTestHelper(1229);
+  RateIncreaseRtpTimestampsTestHelper(1237);
 }
 
 TEST_F(RemoteBitrateEstimatorAbsSendTimeTest, CapacityDropOneStream) {
   CapacityDropTestHelper(1, false, 667);
 }
 
 TEST_F(RemoteBitrateEstimatorAbsSendTimeTest, CapacityDropOneStreamWrap) {
   CapacityDropTestHelper(1, true, 667);
 }
 
@@ skipping 229 matching lines @@
   }
 
   // Wait long enough so that we can call Process again.
   clock_.AdvanceTimeMilliseconds(1000);
 
   bitrate_estimator_->Process();
   EXPECT_TRUE(bitrate_observer_->updated());
   EXPECT_NEAR(bitrate_observer_->latest_bitrate(), 800000u, 10000);
 }
 }  // namespace webrtc