Switch to double for time calculations using playback rate.

media/filters/audio_clock_unittest.cc

Index: media/filters/audio_clock_unittest.cc
diff --git a/media/filters/audio_clock_unittest.cc b/media/filters/audio_clock_unittest.cc
index 7b4d85fd0668431046bc0f3953fe5f0031b35e02..3fe437ee24c6f42829281a47ec698bfa3e74818f 100644
--- a/media/filters/audio_clock_unittest.cc
+++ b/media/filters/audio_clock_unittest.cc
@@ -19,7 +19,7 @@ class AudioClockTest : public testing::Test {
   void WroteAudio(int frames_written,
                   int frames_requested,
                   int delay_frames,
-                  float playback_rate) {
+                  double playback_rate) {
     clock_.WroteAudio(
         frames_written, frames_requested, delay_frames, playback_rate);
   }