Revert 150591 - Remove Pipeline::kEnded state as it is redundant with Pipeline::kStarted.

media/base/pipeline.cc

Index: media/base/pipeline.cc
===================================================================
--- media/base/pipeline.cc	(revision 150598)
+++ media/base/pipeline.cc	(working copy)
@@ -151,6 +151,7 @@
     case kSeeking:
     case kStarting:
     case kStarted:
+    case kEnded:
       return true;
     default:
       return false;
@@ -795,7 +796,7 @@
   DCHECK(!IsPipelineStopPending());
 
   // Suppress seeking if we're not fully started.
-  if (state_ != kStarted) {
+  if (state_ != kStarted && state_ != kEnded) {
     // TODO(scherkus): should we run the callback?  I'm tempted to say the API
     // will only execute the first Seek() request.
     DVLOG(1) << "Media pipeline has not started, ignoring seek to "
@@ -808,7 +809,7 @@
 
   // We'll need to pause every filter before seeking.  The state transition
   // is as follows:
-  //   kStarted
+  //   kStarted/kEnded
   //   kPausing (for each filter)
   //   kSeeking (for each filter)
   //   kStarting (for each filter)
@@ -853,6 +854,8 @@
     return;
   }
 
+  // Transition to ended, executing the callback if present.
+  SetState(kEnded);
   {
     base::AutoLock auto_lock(lock_);
     clock_->EndOfStream();
@@ -987,6 +990,7 @@
     case kStarting:
     case kStopped:
     case kStarted:
+    case kEnded:
       NOTREACHED() << "Unexpected state for teardown: " << state_;
       break;
     // default: intentionally left out to force new states to cause compiler
@@ -1215,6 +1219,7 @@
       break;
 
     case kStarted:
+    case kEnded:
       SetState(kPausing);
       DoPause(base::Bind(&Pipeline::OnTeardownStateTransition, this));
       break;