Squash merge from the widevine repo of several changes to oemcrypto unit tests and the mock reference code. http://go/wvgerrit/16264 Use unsigned int for count in usage table (more mock) http://go/wvgerrit/16262 Use unsigned int for count in usage table (mock version) http://go/wvgerrit/16247 Fix mock OEMCrypto_DeleteUsageTable http://go/wvgerrit/16070 Fix OEMCrypto_GenerateRSASignature return values http://go/wvgerrit/15991 Fix buffer overflow for 32-bit systems http://go/wvgerrit/15993 Return Correct Value from OEMCrypto_RefreshKeys http://go/wvgerrit/15880 Cast RSA_size() to int http://go/wvgerrit/15831 Be strict about warnings for CE CDM b/23729420 b/25221168 Change-Id: I97b91dfc672db8c586ae317977871b7d6afac4bb