Added reference counting to the Pipeline interface.

media/base/pipeline_impl.h

Index: media/base/pipeline_impl.h
diff --git a/media/base/pipeline_impl.h b/media/base/pipeline_impl.h
index 6b97c946d863b059a2ab1db002541f395aa5051f..3efcbe4fac560172d94fb523caf89cf06ab5feb2 100644
--- a/media/base/pipeline_impl.h
+++ b/media/base/pipeline_impl.h
@@ -30,7 +30,6 @@ class PipelineInternal;
 class PipelineImpl : public Pipeline {
  public:
   PipelineImpl(MessageLoop* message_loop);
-  virtual ~PipelineImpl();
 
   // Pipeline implementation.
   virtual bool Start(FilterFactory* filter_factory,
@@ -56,6 +55,7 @@ class PipelineImpl : public Pipeline {
  private:
   friend class FilterHostImpl;
   friend class PipelineInternal;
+  virtual ~PipelineImpl();
 
   // Reset the state of the pipeline object to the initial state.  This method
   // is used by the constructor, and the Stop method.