Provision to start base::SimpleTestTickClock at initial ticks

components/data_usage/android/traffic_stats_amortizer_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/data_usage/android/traffic_stats_amortizer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
@@ skipping 129 matching lines @@
   bool next_traffic_stats_available_;
   int64_t next_traffic_stats_tx_bytes_;
   int64_t next_traffic_stats_rx_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(TestTrafficStatsAmortizer);
 };
 
 class TrafficStatsAmortizerTest : public testing::Test {
  public:
   TrafficStatsAmortizerTest()
-      : test_tick_clock_(new base::SimpleTestTickClock()),
+      : test_tick_clock_(new base::SimpleTestTickClock(base::TimeTicks())),
         mock_timer_(new MockTimerWithTickClock(false, false, test_tick_clock_)),
         amortizer_(scoped_ptr<base::TickClock>(test_tick_clock_),
                    scoped_ptr<base::Timer>(mock_timer_)),
         data_use_callback_call_count_(0) {}
 
   ~TrafficStatsAmortizerTest() override {
     EXPECT_FALSE(mock_timer_->IsRunning());
   }
 
   // Simulates the passage of time by |delta|, firing timers when appropriate.
@@ skipping 508 matching lines @@
                                       1000 * kExpectedBufSize, 1);
   histogram_tester.ExpectUniqueSample(kAmortizationDelayHistogram, 0, 1);
   histogram_tester.ExpectUniqueSample(kBufferSizeOnFlushHistogram,
                                       kExpectedBufSize, 1);
 }
 
 }  // namespace
 
 }  // namespace android
 }  // namespace data_usage