Initial v17 Release

Headers and Unit tests have been updated to match the v17 spec.

Documentation can be found here:
https://developers.devsite.corp.google.com/widevine/drm/client/oemcrypto/v17

util/test/test_clock.cpp

@@ -4,20 +4,19 @@
 //
 // Clock - A fake clock just for running tests.
 
-#include "clock.h"
-
 #include <chrono>
 
+#include "clock.h"
 #include "test_sleep.h"
 
-namespace wvcdm {
+namespace wvutil {
 
 namespace {
 // A fake clock that only advances when TestSleep::Sleep is called.
 class FakeClock : public wvcdm::TestSleep::CallBack {
  public:
   FakeClock() {
-    auto now = std::chrono::steady_clock().now();
+    auto now = std::chrono::system_clock().now();
     now_ = now.time_since_epoch() / std::chrono::milliseconds(1);
     TestSleep::set_callback(this);
   }
@@ -40,4 +39,4 @@ int64_t Clock::GetCurrentTime() {
   return g_fake_clock->now() / 1000;
 }
 
-}  // namespace wvcdm
+}  // namespace wvutil