Initial import of Widevine Common Encryption DRM engine

Builds libwvmdrmengine.so, which is loaded by the new
MediaDrm APIs to support playback of Widevine/CENC
protected content.

Change-Id: I6f57dd37083dfd96c402cb9dd137c7d74edc8f1c

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -0,0 +1,83 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+
+#ifndef CDM_BASE_POLICY_ENGINE_H_
+#define CDM_BASE_POLICY_ENGINE_H_
+
+#include <string>
+
+#include "license_protocol.pb.h"
+#include "wv_cdm_types.h"
+
+namespace wvcdm {
+
+// This acts as an oracle that basically says "Yes(true) you may still decrypt
+// or no(false) you may not decrypt this data anymore."
+class PolicyEngine {
+ public:
+  PolicyEngine();
+  ~PolicyEngine();
+
+  // |current_time| is used to check if license has to be renewed or expired.
+  void OnTimerEvent(int64_t current_time, bool event_occurred, CdmEventType& event);
+
+  // SetLicense is used in handling the initial license response. It stores
+  // an exact copy of the policy information stored in the license.
+  // The license state transitions to kLicenseStateCanPlay if the license
+  // permits playback.
+  void SetLicense(const video_widevine_server::sdk::License& license);
+
+  // UpdateLicense is used in handling a license response for a renewal request.
+  // The response may only contain any policy fields that have changed. In this
+  // case an exact copy is not what we want to happen. We also will receive an
+  // updated license_start_time from the server. The license will transition to
+  // kLicenseStateCanPlay if the license permits playback.
+  void UpdateLicense(const video_widevine_server::sdk::License& license);
+
+  const video_widevine_server::sdk::LicenseIdentification& license_id() {
+    return license_id_;
+  }
+
+ private:
+  typedef enum {
+    kLicenseStateInitial,
+    kLicenseStateCanPlay,
+    kLicenseStateCannotPlay,
+    kLicenseStateNeedRenewal,
+    kLicenseStateWaitingLicenseUpdate,
+    kLicenseStateExpired
+  } LicenseState;
+
+  bool IsLicenseDurationExpired(int64_t current_time);
+  bool IsRenewalDelayExpired(int64_t current_time);
+  bool IsRenewalRecoveryDurationExpired(int64_t current_time);
+  bool IsRenewalRetryIntervalExpired(int64_t current_time);
+
+  void UpdateRenewalRequest(int64_t current_time);
+
+  LicenseState license_state_;
+
+  // This is the current policy information for this license. This gets updated
+  // as license renewals occur.
+  video_widevine_server::sdk::License::Policy policy_;
+
+  // This is the license id field from server response. This data gets passed
+  // back to the server in each renewal request. When we get a renewal response
+  // from the license server we will get an updated id field.
+  video_widevine_server::sdk::LicenseIdentification license_id_;
+
+  // This is the license start time that gets sent from the server in each
+  // license request or renewal.
+  int64_t license_start_time_;
+
+  // This is used as a reference point for policy management. This value
+  // represents an offset from license_start_time_. This is used to calculate
+  // the time where renewal retries should occur.
+  int64_t next_renewal_time_;
+  int64_t policy_max_duration_seconds_;
+
+  CORE_DISALLOW_COPY_AND_ASSIGN(PolicyEngine);
+};
+}  // wvcdm
+
+#endif  // CDM_BASE_POLICY_ENGINE_H_
+