media::SilentSinkSuspender should simulate |delay| and |delay_timestamp|

media/base/silent_sink_suspender_unittest.cc

Index: media/base/silent_sink_suspender_unittest.cc
diff --git a/media/base/silent_sink_suspender_unittest.cc b/media/base/silent_sink_suspender_unittest.cc
index 4434d69d658f763f7a8b9944ae9de7b9bbef27e7..c22c042e30c1352b116e56811545c530d065930b 100644
--- a/media/base/silent_sink_suspender_unittest.cc
+++ b/media/base/silent_sink_suspender_unittest.cc
@@ -49,9 +49,12 @@ class SilentSinkSuspenderTest : public testing::Test {
 
 TEST_F(SilentSinkSuspenderTest, BasicPassthough) {
   temp_bus_->Zero();
+  auto delay = base::TimeDelta::FromMilliseconds(20);
   EXPECT_EQ(temp_bus_->frames(),
-            suspender_.Render(base::TimeDelta(), base::TimeTicks(), 0,
-                              temp_bus_.get()));
+            suspender_.Render(delay, base::TimeTicks(), 0, temp_bus_.get()));
+
+  // Delay should remain.
+  EXPECT_EQ(delay, fake_callback_.last_delay());
   EXPECT_FALSE(temp_bus_->AreFramesZero());
 }