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.

plugin/include/widevine_media_cas.h

@@ -0,0 +1,59 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+
+#ifndef WIDEVINE_MEDIA_CAS_H
+#define WIDEVINE_MEDIA_CAS_H
+
+#include "media/cas/CasAPI.h"
+
+using android::CasFactory;
+using android::CasPlugin;
+using android::CasPluginCallback;
+using android::CasPluginCallbackExt;
+using android::CasPluginDescriptor;
+using android::status_t;
+using android::String8;
+
+extern "C" {
+android::CasFactory* createCasFactory();
+}
+
+namespace wvcas {
+
+// WidevineCasFactory implements the android::CasFactory interface.
+class WidevineCasFactory : public CasFactory {
+ public:
+  // Implements android::CasFactory* createCasFactory(). This method is used
+  // by the MediaCas framework to construct our factory.
+  static WidevineCasFactory* createCasFactory();
+  ~WidevineCasFactory() override {}
+
+  // Test the input |CA_system_id| and return true if it is supported.
+  // We only support the Widevine CA ID.
+  bool isSystemIdSupported(int32_t CA_system_id) const override;
+
+  // Add a descriptor to the vector |descriptors| for each CA ID we support.
+  // We only support the Widevine CA ID.
+  status_t queryPlugins(
+      std::vector<CasPluginDescriptor>* descriptors) const override;
+
+  // Construct an instance of our CAS API plugin.
+  status_t createPlugin(int32_t CA_system_id, void* appData,
+                        CasPluginCallback callback,
+                        CasPlugin** plugin) override;
+
+  // Construct a new extend instance of a CasPlugin given a CA_system_id
+  status_t createPlugin(int32_t CA_system_id, void* appData,
+                        CasPluginCallbackExt callback,
+                        CasPlugin** plugin) override;
+
+ private:
+  WidevineCasFactory() {}
+  WidevineCasFactory(const WidevineCasFactory&);
+  WidevineCasFactory& operator=(const WidevineCasFactory&);
+};
+
+}  // namespace wvcas
+
+#endif  // WIDEVINE_MEDIA_CAS_H