Squashed commit of the following CDM changes:

* Add additional parameters to CDM decryption API
  https://widevine-internal-review.googlesource.com/#/c/6500/

* Pass Length and Flags Parameters to Decrypt()
  https://widevine-internal-review.googlesource.com/#/c/6740/

* Remove core files from oemcrypto/mock
  https://widevine-internal-review.googlesource.com/#/c/6853/

Change-Id: I1c73f5454da20da99130b161543fb990e16e7130

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -85,16 +85,7 @@ class CdmEngine : public TimerHandler {
   // Decryption and key related methods
   // Accept encrypted buffer and return decrypted data.
   virtual CdmResponseType Decrypt(const CdmSessionId& session_id,
-                                  bool is_encrypted,
-                                  bool is_secure,
-                                  const KeyId& key_id,
-                                  const uint8_t* encrypt_buffer,
-                                  size_t encrypt_length,
-                                  const std::vector<uint8_t>& iv,
-                                  size_t block_offset,
-                                  void* decrypt_buffer,
-                                  size_t decrypt_buffer_offset,
-                                  bool is_video);
+                                  const CdmDecryptionParameters& parameters);
 
   // Is the key known to any session?
   virtual bool IsKeyValid(const KeyId& key_id);