Usage Table for Level 3 OEMCrypto

This is a copy of the widevine CL.
https://widevine-internal-review.googlesource.com/#/c/10174/

This CL adds the OEMCrypto v9 functionality to the level 3 haystack
version of OEMCrypto.  Mostly, this is to support usage tables.

The code is feature complete, but the timing tests are a little flakey
-- I'm not sure if the problem is in the code or if the test has too
tight a tolerance.

Also, the storage of the generation number needs to be made more
secure.

Change-Id: I73fecf8934b6a46785f1f8b6f40b40ffe39b88de

libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp

@@ -814,7 +814,7 @@ extern "C" OEMCryptoResult OEMCrypto_DeleteUsageEntry(OEMCrypto_SESSION session,
   LevelSession pair = kAdapter->get(session);
   if (!pair.fcn) return OEMCrypto_ERROR_INVALID_SESSION;
   if( pair.fcn->version > 8 ) {
-    return pair.fcn->DeleteUsageEntry(session, pst, pst_length, message,
+    return pair.fcn->DeleteUsageEntry(pair.session, pst, pst_length, message,
                                       message_length, signature,
                                       signature_length);
   } else {

libwvdrmengine/cdm/core/src/oemcrypto_adapter_static_v8.cpp

@@ -76,7 +76,7 @@ extern "C" OEMCryptoResult OEMCrypto_LoadKeys(
     const uint8_t* enc_mac_key_iv, const uint8_t* enc_mac_key, size_t num_keys,
     const OEMCrypto_KeyObject* key_array,
     const uint8_t* pst, size_t pst_length) {
-  return OEMCrypto_LoadKeys_V8(session, message, message_length, signature,
+  return OEMCrypto_LoadKeys_V8(pair.session, message, message_length, signature,
                                signature_length, enc_mac_key_iv, enc_mac_key,
                                num_keys, key_array);
 }