Nice and easy fix for the media clock interpolating past the duration.

media/base/mock_filters.h

 // Copyright (c) 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.
 //
 // A new breed of mock media filters, this time using gmock!  Feel free to add
 // actions if you need interesting side-effects (i.e., copying data to the
 // buffer passed into MockDataSource::Read()).
 //
 // Don't forget you can use StrictMock<> and NiceMock<> if you want the mock
 // filters to fail the test or do nothing when an unexpected method is called.
@@ skipping 318 matching lines @@
 // Helper gmock function that immediately destroys the FilterCallback on behalf
 // of the provided filter.  Can be used when mocking the Initialize() and Seek()
 // methods.
 void DestroyFilterCallback(::testing::Unused, FilterCallback* callback);
 
 // Helper gmock action that calls SetError() on behalf of the provided filter.
 ACTION_P2(SetError, filter, error) {
   filter->host()->SetError(error);
 }
 
+// Helper gmock action that calls SetDuration() on behalf of the provided
+// filter.
+ACTION_P2(SetDuration, filter, duration) {
+  filter->host()->SetDuration(duration);
+}
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_MOCK_FILTERS_H_