Switch to double for time calculations using playback rate.

media/renderers/renderer_impl_unittest.cc

Index: media/renderers/renderer_impl_unittest.cc
diff --git a/media/renderers/renderer_impl_unittest.cc b/media/renderers/renderer_impl_unittest.cc
index 75fc0500dd18b820639cc9b05151c03fe5138af7..41c1c2ff397aae543ddfdc7ade8a5586feee2427 100644
--- a/media/renderers/renderer_impl_unittest.cc
+++ b/media/renderers/renderer_impl_unittest.cc
@@ -230,7 +230,7 @@ class RendererImplTest : public ::testing::Test {
     return renderer_impl_->GetMediaTime().InMilliseconds();
   }
 
-  bool IsMediaTimeAdvancing(float playback_rate) {
+  bool IsMediaTimeAdvancing(double playback_rate) {
     int64 start_time_ms = GetMediaTimeMs();
     const int64 time_to_advance_ms = 100;
 
@@ -245,7 +245,7 @@ class RendererImplTest : public ::testing::Test {
   }
 
   bool IsMediaTimeAdvancing() {
-    return IsMediaTimeAdvancing(1.0f);
+    return IsMediaTimeAdvancing(1.0);
   }
 
   // Fixture members.