Bug 1048097 - Delete the GMPBuffer we send into GMP/CDM for decryption once it's been returned decrypted. r=jesup
Bug 1048102 - Delete GMPThreads as they're joined. r=jesup
Bug 1048104 - Add GMPMutex::Destroy(). r=jesup
Bug 1048107 - Add GMPTimer implementation and placeholder GMP clock. r=jesup