Correct KeySetId value when returned by AddKey

[ Merge of http://go/wvgerrit/25643 ]

The MediaDrm#provideKeyResponse API states that an empty byte array is
returned when the license type is streaming or release but a non-empty
value was being returned in some cases.

The KeySetId is now returned when the license type is offline or when
the license is streaming and has a secure stop associated with it.

Test: Verified by request_license_test integration tests. Tests have been
      modified to validate the returned Key Set Id values.

b/36093612

Change-Id: I82dba537c77ddd1d1876cbce58729f3db901ee51

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -79,7 +79,26 @@ class CdmEngine {
       const CdmSessionId& session_id, const CdmKeySetId& key_set_id,
       const InitializationData& init_data, const CdmLicenseType license_type,
       CdmAppParameterMap& app_parameters, CdmKeyRequest* key_request);
-  // Accept license response and extract key info.
+  // This API may
+  // (a) accept license response, extract key info and load keys.
+  // (b) accept a renewal response and update license policy information.
+  // (c) accept a release response and release an offline license or secure
+  //     stop.
+  // (d) accept a service certificate and cache that information for the
+  //     the lifetime of the session.
+  //
+  // |session_id| identifies the session that generated the request and can
+  //              process the response. Should be empty if a release response.
+  // |key_data| is the license, renewal, release response or service
+  //            certificate response.
+  // |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
+  //              be filled in on return. Use the |key_set_id| with
+  //              RestoreKeys (to reload offline session) or
+  //              GenerateKeyRequest (to release offline session/secure stop).
+  //              |key_set_id| will be cleared if release or streaming
+  //              (not associated with a secure stop).
   virtual CdmResponseType AddKey(const CdmSessionId& session_id,
                                  const CdmKeyResponse& key_data,
                                  CdmKeySetId* key_set_id);

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -117,6 +117,10 @@ class CdmSession {
   virtual bool is_offline() { return is_offline_; }
   virtual bool is_temporary() { return is_temporary_; }
   virtual bool license_received() { return license_received_; }
+  virtual bool has_provider_session_token() {
+    return (license_parser_.get() != NULL &&
+        license_parser_->provider_session_token().size() > 0);
+  }
 
   virtual CdmUsageSupportType get_usage_support_type()
       { return usage_support_type_; }

libwvdrmengine/cdm/core/src/cdm_engine.cpp

@@ -363,7 +363,13 @@ CdmResponseType CdmEngine::AddKey(const CdmSessionId& session_id,
 
   CdmResponseType sts = iter->second->AddKey(key_data);
   if (key_set_id) {
-    *key_set_id = iter->second->key_set_id();
+    if ((iter->second->is_offline() ||
+         iter->second->has_provider_session_token()) &&
+      !license_type_release) {
+      *key_set_id = iter->second->key_set_id();
+    } else {
+      key_set_id->clear();
+    }
   }
 
   switch (sts) {

libwvdrmengine/cdm/core/src/cdm_session.cpp

@@ -185,6 +185,9 @@ CdmResponseType CdmSession::Init(CdmClientPropertySet* cdm_client_property_set,
 
 CdmResponseType CdmSession::RestoreOfflineSession(
     const CdmKeySetId& key_set_id, const CdmLicenseType license_type) {
+  if (!key_set_id_.empty()) {
+    file_handle_->UnreserveLicenseId(key_set_id_);
+  }
   key_set_id_ = key_set_id;
 
   DeviceFiles::LicenseState license_state;
@@ -456,7 +459,7 @@ CdmResponseType CdmSession::AddKey(const CdmKeyResponse& key_response) {
     license_received_ = true;
     key_response_ = key_response;
 
-    if (is_offline_ || !license_parser_->provider_session_token().empty()) {
+    if (is_offline_ || has_provider_session_token()) {
       if (usage_support_type_ == kUsageEntrySupport)
         usage_table_header_->UpdateEntry(crypto_session_.get(), &usage_entry_);
 
@@ -562,8 +565,7 @@ CdmResponseType CdmSession::Decrypt(const CdmDecryptionParameters& params) {
     }
     has_decrypted_since_last_report_ = true;
     if (!is_usage_update_needed_) {
-      is_usage_update_needed_ =
-          !license_parser_->provider_session_token().empty();
+      is_usage_update_needed_ = has_provider_session_token();
     }
   } else {
     Clock clock;
@@ -647,7 +649,7 @@ CdmResponseType CdmSession::ReleaseKey(const CdmKeyResponse& key_response) {
       license_parser_->HandleKeyUpdateResponse(false, key_response);
   if (sts != KEY_ADDED) return (sts == KEY_ERROR) ? RELEASE_KEY_ERROR : sts;
 
-  if (is_offline_ || !license_parser_->provider_session_token().empty()) {
+  if (is_offline_ || has_provider_session_token()) {
     DeleteLicense();
 
     // Deletion of usage entry cannot occur while in use by a crypto session.
@@ -780,7 +782,7 @@ CdmResponseType CdmSession::ReleaseCrypto() {
 }
 
 bool CdmSession::DeleteLicense() {
-  if (!is_offline_ && license_parser_->provider_session_token().empty())
+  if (!is_offline_ && !has_provider_session_token())
     return false;
 
   if (is_offline_) {