Implement disabling and enabling media tracks

media/renderers/renderer_impl_unittest.cc

Index: media/renderers/renderer_impl_unittest.cc
diff --git a/media/renderers/renderer_impl_unittest.cc b/media/renderers/renderer_impl_unittest.cc
index 97900551f4d455206f28337f704e08a48d8d1928..d92dad4c4ad450e5d8f990ab7b65aa3a0efc9bc8 100644
--- a/media/renderers/renderer_impl_unittest.cc
+++ b/media/renderers/renderer_impl_unittest.cc
@@ -87,6 +87,7 @@ class RendererImplTest : public ::testing::Test {
       DemuxerStream::Type type) {
     std::unique_ptr<StrictMock<MockDemuxerStream>> stream(
         new StrictMock<MockDemuxerStream>(type));
+    EXPECT_CALL(*stream, SetStreamRestartedCB(_)).Times(testing::AnyNumber());
     return stream;
   }