Pipeline will execute a callback whenever an run-time error has happened....

media/base/pipeline_impl.cc

 // Copyright (c) 2008-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // TODO(scherkus): clean up PipelineImpl... too many crazy function names,
 // potential deadlocks, etc...
 
 #include "base/compiler_specific.h"
 #include "base/condition_variable.h"
 #include "base/stl_util-inl.h"
@@ skipping 219 matching lines @@
   AutoLock auto_lock(lock_);
   *width_out = video_width_;
   *height_out = video_height_;
 }
 
 PipelineError PipelineImpl::GetError() const {
   AutoLock auto_lock(lock_);
   return error_;
 }
 
+void PipelineImpl::SetPipelineErrorCallback(PipelineCallback* error_callback) {
+  error_callback_.reset(error_callback);
+}
+
 void PipelineImpl::ResetState() {
   AutoLock auto_lock(lock_);
   running_          = false;
   duration_         = base::TimeDelta();
   buffered_time_    = base::TimeDelta();
   buffered_bytes_   = 0;
   total_bytes_      = 0;
   video_width_      = 0;
   video_height_     = 0;
   volume_           = 1.0f;
@@ skipping 276 matching lines @@
     seek_callback_->Run();
   }
   seek_callback_.reset();
   filter_factory_ = NULL;
 
   // We no longer need to examine our previous state, set it to stopped.
   state_ = kError;
 
   // Destroy every filter and reset the pipeline as well.
   DestroyFilters();
+
+  // If our owner has requested to be notified of an error, execute
+  // |error_callback_| unless we have a "good" error.
+  if (error_callback_.get() && error != PIPELINE_STOPPING) {
+    error_callback_->Run();
+  }
 }
 
 void PipelineImpl::PlaybackRateChangedTask(float playback_rate) {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
   for (FilterVector::iterator iter = filters_.begin();
        iter != filters_.end();
        ++iter) {
     (*iter)->SetPlaybackRate(playback_rate);
   }
 }
@@ skipping 246 matching lines @@
 
   // Reset the pipeline, which will decrement a reference to this object.
   // We will get destroyed as soon as the remaining tasks finish executing.
   // To be safe, we'll set our pipeline reference to NULL.
   filters_.clear();
   filter_types_.clear();
   STLDeleteElements(&filter_threads_);
 }
 
 }  // namespace media