Refactor PipelineImpl to use CompositeFilter to manage Filter state transitions.

media/base/mock_filters.cc

 // Copyright (c) 2010 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.
 
 #include "media/base/mock_filters.h"
 
 namespace media {
 
 void RunFilterCallback(::testing::Unused, FilterCallback* callback) {
   callback->Run();
   delete callback;
 }
 
 void DestroyFilterCallback(::testing::Unused, FilterCallback* callback) {
   delete callback;
 }
 
 void RunStopFilterCallback(FilterCallback* callback) {
   callback->Run();
   delete callback;
 }
 
+MockFilter::MockFilter() :
+    requires_message_loop_(false) {
+}
+
+MockFilter::MockFilter(bool requires_message_loop) :
+    requires_message_loop_(requires_message_loop) {
+}
+
+MockFilter::~MockFilter() {}
+
+bool MockFilter::requires_message_loop() const {
+  return requires_message_loop_;
+}
+
+const char* MockFilter::message_loop_name() const {
+  return "MockFilter";
+}
+
+
 }  // namespace media