Provision to start base::SimpleTestTickClock at initial ticks

media/cast/net/rtcp/rtcp_utility_unittest.cc

Index: media/cast/net/rtcp/rtcp_utility_unittest.cc
diff --git a/media/cast/net/rtcp/rtcp_utility_unittest.cc b/media/cast/net/rtcp/rtcp_utility_unittest.cc
index 66abc9a0f500b4a77fa9bc92d796b935b1f11eec..a9b76552af9988203525d56b56de75380ed70316 100644
--- a/media/cast/net/rtcp/rtcp_utility_unittest.cc
+++ b/media/cast/net/rtcp/rtcp_utility_unittest.cc
@@ -26,10 +26,9 @@ static const base::TimeDelta kTargetDelay =
 class RtcpParserTest : public ::testing::Test {
  protected:
   RtcpParserTest()
-      : testing_clock_(new base::SimpleTestTickClock()),
-        task_runner_(new test::FakeSingleThreadTaskRunner(
-            testing_clock_.get())) {
-  }
+      : testing_clock_(new base::SimpleTestTickClock(base::TimeTicks())),
+        task_runner_(
+            new test::FakeSingleThreadTaskRunner(testing_clock_.get())) {}
 
   bool HasAnything(const RtcpParser& parser) {
     return parser.has_sender_report() ||
@@ -328,8 +327,8 @@ TEST_F(RtcpParserTest, InjectReceiverReportWithReceiverLogVerificationBase) {
   static const uint32_t kTimeBaseMs = 12345678;
   static const uint32_t kTimeDelayMs = 10;
   static const uint32_t kDelayDeltaMs = 123;
-  base::SimpleTestTickClock testing_clock;
-  testing_clock.Advance(base::TimeDelta::FromMilliseconds(kTimeBaseMs));
+  base::SimpleTestTickClock testing_clock(
+      base::TimeTicks() + base::TimeDelta::FromMilliseconds(kTimeBaseMs));
 
   RtcpReceiverLogMessage receiver_log;
   RtcpReceiverFrameLogMessage frame_log(kRtpTimestamp);
@@ -371,8 +370,8 @@ TEST_F(RtcpParserTest, InjectReceiverReportWithReceiverLogVerificationMulti) {
   static const uint32_t kTimeBaseMs = 12345678;
   static const uint32_t kTimeDelayMs = 10;
   static const int kDelayDeltaMs = 123;  // To be varied for every frame.
-  base::SimpleTestTickClock testing_clock;
-  testing_clock.Advance(base::TimeDelta::FromMilliseconds(kTimeBaseMs));
+  base::SimpleTestTickClock testing_clock(
+      base::TimeTicks() + base::TimeDelta::FromMilliseconds(kTimeBaseMs));
 
   RtcpReceiverLogMessage receiver_log;