Report change in session expiration

Bug: 19771612

Merged from Widevine CDM repo:
https://widevine-internal-review.googlesource.com/#/c/13885/

Change-Id: I754f06a7ed9476554f9e1da3fe23f4563f9fc07e

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -63,8 +63,12 @@ class PolicyEngine {
 
   virtual const LicenseIdentification& license_id() { return license_id_; }
 
-  bool IsLicenseDurationExpired(int64_t current_time);
-  bool IsPlaybackDurationExpired(int64_t current_time);
+  bool IsLicenseDurationExpired(int64_t current_time) {
+    return GetLicenseExpiryTime() <= current_time;
+  }
+  bool IsPlaybackDurationExpired(int64_t current_time) {
+    return GetPlaybackExpiryTime() <= current_time;
+  }
 
   bool GetSecondsSinceStarted(int64_t* seconds_since_started);
   bool GetSecondsSinceLastPlayed(int64_t* seconds_since_started);
@@ -89,6 +93,9 @@ class PolicyEngine {
     kLicenseStateExpired
   } LicenseState;
 
+  int64_t GetLicenseExpiryTime();
+  int64_t GetPlaybackExpiryTime();
+
   int64_t GetLicenseDurationRemaining(int64_t current_time);
   int64_t GetPlaybackDurationRemaining(int64_t current_time);
 
@@ -98,6 +105,10 @@ class PolicyEngine {
 
   void UpdateRenewalRequest(int64_t current_time);
 
+  // Notifies updates in expiry time and fire OnExpirationUpdate event if
+  // expiry time changes.
+  void NotifyExpirationUpdate();
+
   // These setters are for testing only. Takes ownership of the pointers.
   void set_clock(Clock* clock);
 
@@ -119,6 +130,7 @@ class PolicyEngine {
   int64_t license_start_time_;
   int64_t playback_start_time_;
   int64_t last_playback_time_;
+  int64_t last_expiry_time_;
 
   // This is used as a reference point for policy management. This value
   // represents an offset from license_start_time_. This is used to

libwvdrmengine/cdm/core/include/wv_cdm_event_listener.h

@@ -15,6 +15,8 @@ class WvCdmEventListener {
 
   virtual void OnSessionRenewalNeeded(const CdmSessionId& session_id) = 0;
   virtual void OnSessionExpiration(const CdmSessionId& session_id) = 0;
+  virtual void OnExpirationUpdate(const CdmSessionId& session_id,
+                                  int64_t new_expiry_time) = 0;
 
  private:
   CORE_DISALLOW_COPY_AND_ASSIGN(WvCdmEventListener);