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

media/base/pipeline_impl_unittest.cc

Index: media/base/pipeline_impl_unittest.cc
===================================================================
--- media/base/pipeline_impl_unittest.cc	(revision 22059)
+++ media/base/pipeline_impl_unittest.cc	(working copy)
@@ -32,6 +32,7 @@
   MOCK_METHOD0(OnStart, void());
   MOCK_METHOD0(OnSeek, void());
   MOCK_METHOD0(OnStop, void());
+  MOCK_METHOD0(OnError, void());
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CallbackHelper);
@@ -48,6 +49,9 @@
   PipelineImplTest()
       : pipeline_(new PipelineImpl(&message_loop_)),
         mocks_(new MockFilterFactory()) {
+    pipeline_->SetPipelineErrorCallback(NewCallback(
+        reinterpret_cast<CallbackHelper*>(&callbacks_),
+        &CallbackHelper::OnError));
   }
 
   virtual ~PipelineImplTest() {
@@ -234,6 +238,7 @@
 }
 
 TEST_F(PipelineImplTest, RequiredFilterMissing) {
+  EXPECT_CALL(callbacks_, OnError());
   mocks_->set_creation_successful(false);
 
   InitializePipeline();
@@ -247,6 +252,7 @@
       .WillOnce(DoAll(SetError(mocks_->data_source(),
                                PIPELINE_ERROR_URL_NOT_FOUND),
                       Invoke(&RunFilterCallback)));
+  EXPECT_CALL(callbacks_, OnError());
   EXPECT_CALL(*mocks_->data_source(), Stop());
 
   InitializePipeline();
@@ -266,6 +272,7 @@
   EXPECT_CALL(*mocks_->demuxer(), GetNumberOfStreams())
       .WillRepeatedly(Return(0));
   EXPECT_CALL(*mocks_->demuxer(), Stop());
+  EXPECT_CALL(callbacks_, OnError());
 
   InitializePipeline();
   EXPECT_FALSE(pipeline_->IsInitialized());