Clean up Pipeline terminal state logic by merging kError into kStopped state.

media/base/pipeline.h

Index: media/base/pipeline.h
diff --git a/media/base/pipeline.h b/media/base/pipeline.h
index 9dfbf556224b56ca1f3844a93290edfd5a9c3ecf..e28e1cbd45bdb2dee026afeb386390c78ebd6bce 100644
--- a/media/base/pipeline.h
+++ b/media/base/pipeline.h
@@ -92,9 +92,7 @@ class MEDIA_EXPORT PipelineStatusNotification {
 // From then on the normal Seek() transitions are carried out and we start
 // playing the media.
 //
-// If any error ever happens, this object will transition to the "Error" state
-// from any state. If Stop() is ever called, this object will transition to
-// "Stopped" state.
+// Any runtime error will cause the pipeline to end up in the stopped state.
 class MEDIA_EXPORT Pipeline
     : public base::RefCountedThreadSafe<Pipeline>,
       public DemuxerHost {
@@ -105,10 +103,6 @@ class MEDIA_EXPORT Pipeline
   // Build a pipeline to using the given filter collection to construct a filter
   // chain.
   //
-  // Pipeline initialization is an inherently asynchronous process.  Clients can
-  // either poll the IsInitialized() method (discouraged) or optionally pass in
-  // |start_cb|, which will be executed when initialization completes.
-  //
   // The following permanent callbacks will be executed as follows:
   //   |start_cb_| will be executed when Start is done (successfully or not).
   //   |ended_cb| will be executed whenever the media reaches the end.
@@ -119,26 +113,14 @@ class MEDIA_EXPORT Pipeline
   // Stop() has completed.
   //
   // It is an error to call this method after the pipeline has already started.
-  //
-  // TODO(scherkus): remove IsInitialized() and force clients to use callbacks.
   void Start(scoped_ptr<FilterCollection> filter_collection,
              const PipelineStatusCB& ended_cb,
              const PipelineStatusCB& error_cb,
              const PipelineStatusCB& start_cb);
 
-  // Asynchronously stops the pipeline and resets it to an uninitialized state.
-  //
-  // If provided, |stop_cb| will be executed when the pipeline has been
-  // completely torn down and reset to an uninitialized state.  It is acceptable
-  // to call Start() again once the callback has finished executing.
+  // Asynchronously stops the pipeline, executing |stop_cb| when completed.
   //
-  // Stop() must be called before destroying the pipeline.  Clients can
-  // determine whether Stop() must be called by checking IsRunning().
-  //
-  // It is an error to call this method if the pipeline has not started.
-  //
-  // TODO(scherkus): ideally clients would destroy the pipeline after calling
-  // Stop() and create a new pipeline as needed.
+  // Clients can delete the pipeline after |stop_cb| runs.
   void Stop(const base::Closure& stop_cb);
 
   // Attempt to seek to the position specified by time.  |seek_cb| will be
@@ -155,11 +137,6 @@ class MEDIA_EXPORT Pipeline
   // the pipeline.
   bool IsRunning() const;
 
-  // Returns true if the pipeline has been started and fully initialized to a
-  // point where playback controls will be respected.  Note that it is possible
-  // for a pipeline to be started but not initialized (i.e., an error occurred).
-  bool IsInitialized() const;
-
   // Returns true if the media has audio.
   bool HasAudio() const;
 
@@ -245,7 +222,6 @@ class MEDIA_EXPORT Pipeline
     kStarted,
     kStopping,
     kStopped,
-    kError,
   };
 
   // Updates |state_|. All state transitions should use this call.
@@ -341,7 +317,7 @@ class MEDIA_EXPORT Pipeline
   void StopTask(const base::Closure& stop_cb);
 
   // Carries out stopping and destroying all filters, placing the pipeline in
-  // the kError state.
+  // the kStopped state.
   void ErrorChangedTask(PipelineStatus error);
 
   // Carries out notifying filters that the playback rate has changed.
@@ -443,15 +419,9 @@ class MEDIA_EXPORT Pipeline
   // Whether or not the pipeline is in transition for a seek operation.
   bool seek_pending_;
 
-  // Whether or not the pipeline is pending a stop operation.
-  bool stop_pending_;

[scherkus (not reviewing), 2012/08/08 02:20:56]

this is equivalent to inspecting stop_cb_

-
   // Whether or not the pipeline is perform a stop operation.
   bool tearing_down_;
 
-  // Whether or not an error triggered the teardown.
-  bool error_caused_teardown_;

[scherkus (not reviewing), 2012/08/08 02:20:56]

this is equivalent to (status_ != PIPELINE_OK)

-
   // Whether or not a playback rate change should be done once seeking is done.
   bool playback_rate_change_pending_;