Bug 1002320 - Switch video readers at the earliest possible point rather than the latest.  r=cajbir
Bug 1002987 - Forward subdecoder frame stats to parent decoder.  r=cajbir
Bug 1002994 - Remove array of old decoders from SourceBuffer, just keep a reference to the current decoder.  r=cajbir
Bug 1002404 - Register subdecoders earlier to avoid missing initialization.  r=cajbir