Certificate provisioning verification

bug: 8620943

This is a merge of changes made to the Widevine CDM
repository during certificate provisioning verification.

The following changes are included:

Fixes for certificate based licensing
https://widevine-internal-review.googlesource.com/#/c/5162/

Base64 encode and decode now handles non-multiple of 24-bits input
https://widevine-internal-review.googlesource.com/#/c/4981/

Fixed issues with device provisioning response handling
https://widevine-internal-review.googlesource.com/#/c/5153/

Persistent storage to support device certificates
https://widevine-internal-review.googlesource.com/#/c/5161/

Enable loading of certificates
https://widevine-internal-review.googlesource.com/#/c/5172/

Provide license server url
https://widevine-internal-review.googlesource.com/#/c/5173/

Change-Id: I0c032c1ae0055dcc1a7a77ad4b0ea0898030dc7d

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -36,7 +36,8 @@ class CdmSession {
   CdmResponseType GenerateKeyRequest(const CdmInitData& pssh_data,
                                      const CdmLicenseType license_type,
                                      CdmAppParameterMap& app_parameters,
-                                     CdmKeyMessage* key_request);
+                                     CdmKeyMessage* key_request,
+                                     std::string* server_url);
 
   // AddKey() - Accept license response and extract key info.
   CdmResponseType AddKey(const CdmKeyResponse& key_response);
@@ -65,7 +66,8 @@ class CdmSession {
   // License renewal
   // GenerateRenewalRequest() - Construct valid renewal request for the current
   // session keys.
-  CdmResponseType GenerateRenewalRequest(CdmKeyMessage* key_request);
+  CdmResponseType GenerateRenewalRequest(CdmKeyMessage* key_request,
+                                         std::string* server_url);
 
   // RenewKey() - Accept renewal response and update key info.
   CdmResponseType RenewKey(const CdmKeyResponse& key_response);