Cas Client repo update.

-Parse EMM in Cas plugin
-Entitlement key rotation support
-Multi_content_license support

plugin/include/emm_parser.h

@@ -0,0 +1,49 @@
+// Copyright 2020 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+
+#ifndef EMM_PARSER_H
+#define EMM_PARSER_H
+
+#include <memory>
+#include <vector>
+
+#include "cas_types.h"
+#include "media_cas.pb.h"
+
+namespace wvcas {
+
+using video_widevine::EmmPayload;
+
+class EmmParser {
+ public:
+  EmmParser(const EmmParser&) = delete;
+  EmmParser& operator=(const EmmParser&) = delete;
+  virtual ~EmmParser() = default;
+
+  // The EmmParser factory method.
+  // The methods validates the passed in |emm|. If validation is successful, it
+  // constructs and returns an EmmParser. Otherwise, nullptr is returned.
+  static std::unique_ptr<const EmmParser> Create(const CasEmm& emm);
+
+  // Accessor methods.
+  virtual uint64_t timestamp() const { return timestamp_; }
+  virtual std::string signature() const { return signature_; }
+  virtual EmmPayload emm_payload() const { return emm_payload_; };
+
+ protected:
+  // Called by the factory create and unit test.
+  EmmParser() = default;
+
+ private:
+  bool Parse(int start_index, const CasEmm& emm);
+
+  uint8_t version_;
+  uint64_t timestamp_;
+  EmmPayload emm_payload_;
+  std::string signature_;
+};
+
+}  // namespace wvcas
+
+#endif  // EMM_PARSER_H