Add a field indicating online vs offline licenses.

Import of http://go/wvgerrit/68188

This adds an attribute to metrics indicating if the license was online
or offline.

Also, added a unit test for CdmEngineMetricsImpl.

Test: Unit tests. GPlay manual. GTS tests.
Bug: 115523917

Change-Id: Id315c643048914a2c51904451f9665987bc87eb7

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -97,6 +97,9 @@ class CdmEngine {
   //              process the response. Should be empty if a release response.
   // |key_data| is the license, renewal, release response or service
   //            certificate response.
+  // |license_type| must not be null. If the result is KEY_ADDED, this out
+  //                parameter indicates the type of license containd in
+  //                key_data. For any other return code, no value is provided.
   // |key_set_id| should be non-null and specified if license release.
   //              If offline license or streaming license associated with
   //              a secure stop, |key_set_id| should be non-null and will
@@ -107,6 +110,7 @@ class CdmEngine {
   //              (not associated with a secure stop).
   virtual CdmResponseType AddKey(const CdmSessionId& session_id,
                                  const CdmKeyResponse& key_data,
+                                 CdmLicenseType* license_type,
                                  CdmKeySetId* key_set_id);
 
   virtual CdmResponseType RestoreKey(const CdmSessionId& session_id,