V18.4.0 CAS plugin

Note that this version does not have Widevine Provisioning 4.0 support.
It is only suitable for device upgrades. A new patch with provisioning
4.0 support will be made later.

wvutil/include/clock.h

@@ -0,0 +1,26 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+//
+// Clock - Platform independent interface for a time library
+//
+#ifndef WVCDM_UTIL_CLOCK_H_
+#define WVCDM_UTIL_CLOCK_H_
+
+#include <stdint.h>
+
+namespace wvutil {
+
+// Provides time related information. The implementation is platform dependent.
+class Clock {
+ public:
+  Clock() {}
+  virtual ~Clock() {}
+
+  // Provides the number of seconds since an epoch - 01/01/1970 00:00 UTC
+  virtual int64_t GetCurrentTime();
+};
+
+}  // namespace wvutil
+
+#endif  // WVCDM_UTIL_CLOCK_H_