Make check for 'opened' consistent across all audio stream implementations of Start() and log an ...

media/audio/pulse/pulse_output.cc

Index: media/audio/pulse/pulse_output.cc
===================================================================
--- media/audio/pulse/pulse_output.cc	(revision 113210)
+++ media/audio/pulse/pulse_output.cc	(working copy)
@@ -383,8 +383,11 @@
 
 void PulseAudioOutputStream::Start(AudioSourceCallback* callback) {
   DCHECK_EQ(message_loop_, MessageLoop::current());
+  CHECK(callback);
+  DLOG_IF(ERROR, !playback_handle_) << "Must call Open() first";
+  if (!playback_handle_)
+    return;
 
-  CHECK(callback);
   source_callback_ = callback;
 
   // Clear buffer, it might still have data in it.