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/cdm_session.h

@@ -28,6 +28,8 @@ class CdmSession {
 
   CdmResponseType RestoreOfflineSession(const CdmKeySetId& key_set_id,
                                         const CdmLicenseType license_type);
+  CdmResponseType RestoreUsageSession(const CdmKeyMessage& key_request,
+                                      const CdmKeyResponse& key_response);
 
   void set_key_system(const CdmKeySystem& ksystem) { key_system_ = ksystem; }
   const CdmKeySystem& key_system() { return key_system_; }
@@ -89,6 +91,12 @@ class CdmSession {
   void OnKeyReleaseEvent(const CdmKeySetId& key_set_id);
 
   SecurityLevel GetRequestedSecurityLevel();
+  CdmSecurityLevel GetSecurityLevel();
+
+  CdmResponseType UpdateUsageInformation();
+
+  bool is_usage_update_needed() { return is_usage_update_needed_; }
+  void reset_is_usage_update_needed() { is_usage_update_needed_ = false; }
 
  private:
 
@@ -96,7 +104,9 @@ class CdmSession {
   CdmSessionId GenerateSessionId();
   bool GenerateKeySetId(CdmKeySetId* key_set_id);
 
+  CdmResponseType StoreLicense();
   bool StoreLicense(DeviceFiles::LicenseState state);
+  bool DeleteLicense();
 
   // instance variables
   const CdmSessionId session_id_;
@@ -106,13 +116,16 @@ class CdmSession {
   PolicyEngine policy_engine_;
   bool license_received_;
   bool reinitialize_session_;
+  bool is_offline_;
+  bool is_release_;
+  bool is_usage_update_needed_;
 
-  CdmLicenseType license_type_;
+  // information useful for offline and usage scenarios
+  CdmKeyMessage key_request_;
+  CdmKeyResponse key_response_;
 
   // license type offline related information
   CdmInitData offline_init_data_;
-  CdmKeyMessage offline_key_request_;
-  CdmKeyResponse offline_key_response_;
   CdmKeyMessage offline_key_renewal_request_;
   CdmKeyResponse offline_key_renewal_response_;
   std::string offline_release_server_url_;