Enable usage reporting

[ Merge from Widevine CDM repo of
  https://widevine-internal-review.googlesource.com/#/c/10171/ and
  https://widevine-internal-review.googlesource.com/#/c/10172/ ]

Updated license_protocol.proto from constituent protos in google3

These changes make use of OEMCrypto v9 changes to support usage reporting.
Usage reporting may be enabled for streaming (by means of secure stops) and
offline playback by a provider session token specified in the license.

Changes include periodically updating usage information for relevant
sessions and reporting and releasing usage information as needed.

The CDM has removed all references to Secure Stops. This change
updates the Android API implementation to comply.

b/11987015

Change-Id: Ibb6f2ced4ef20ee349ca1ae6412ce686b2b5d085

libwvdrmengine/cdm/core/include/crypto_session.h

@@ -45,7 +45,8 @@ class CryptoSession {
                            const std::string& signature,
                            const std::string& mac_key_iv,
                            const std::string& mac_key,
-                           int num_keys, const CryptoKey* key_array);
+                           const std::vector<CryptoKey>& key_array,
+                           const std::string& provider_session_token);
   bool LoadCertificatePrivateKey(std::string& wrapped_key);
   bool RefreshKeys(const std::string& message, const std::string& signature,
                    int num_keys, const CryptoKey* key_array);
@@ -63,6 +64,15 @@ class CryptoSession {
   // Media data path
   CdmResponseType Decrypt(const CdmDecryptionParameters& parameters);
 
+  CdmResponseType UpdateUsageInformation();
+  CdmResponseType GenerateUsageReport(
+      const std::string& provider_session_token,
+      std::string* usage_report);
+  CdmResponseType ReleaseUsageInformation(
+      const std::string& message,
+      const std::string& signature,
+      const std::string& provider_session_token);
+
   bool GetRandom(size_t data_length, uint8_t* random_data);
 
  private: