Refactor rtc_unittests into several targets.

webrtc/base/ratetracker_unittest.cc

 /*
  *  Copyright 2015 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.
  */
 
 #include "webrtc/base/gunit.h"
 #include "webrtc/base/ratetracker.h"
 
 namespace rtc {
 namespace {
   const uint32_t kBucketIntervalMs = 100;
 }  // namespace
 
 class RateTrackerForTest : public RateTracker {
  public:
   RateTrackerForTest() : RateTracker(kBucketIntervalMs, 10u), time_(0) {}
-  virtual int64_t Time() const { return time_; }
+  int64_t Time() const override { return time_; }
   void AdvanceTime(int delta) { time_ += delta; }
 
  private:
   int64_t time_;
 };
 
 TEST(RateTrackerTest, Test30FPS) {
   RateTrackerForTest tracker;
 
   for (int i = 0; i < 300; ++i) {
@@ skipping 126 matching lines @@
 }
 
 TEST(RateTrackerTest, TestGetUnitSecondsAfterInitialValue) {
   RateTrackerForTest tracker;
   tracker.AddSamples(1234);
   tracker.AdvanceTime(1000);
   EXPECT_DOUBLE_EQ(1234.0, tracker.ComputeRateForInterval(1000));
 }
 
 }  // namespace rtc