Refactor oemcrypto mock into stand alone reference code

Merge from Widevine repo of http://go/wvgerrit/46204
Refactor utility code - split the mock, step 1

Merge from Widevine repo of http://go/wvgerrit/46205
Move some OEMCrypto types to common header - split the mock, step 2

Merge from Widevine repo of http://go/wvgerrit/46206
Split mock into two -- step 3

Merge from Widevine repo of http://go/wvgerrit/47460
Split the mock into two -- step 3.5

The CL moves several files used by oemcrypto and cdm into a common
subdirectory, so that it may more easily be shared with partners.

The CORE_DISALLOW_COPY_AND_ASSIGN macro was moved to its own header in
the util/include directory.

This CL removes some references to the mock from other code, and puts
some constants and types, such as the definition of the keybox, into a
header in oemcrypto.

Test: tested as part of http://go/ag/4674759
bug: 76393338
Change-Id: I75b4bde7062ed8ee572c97ebc2f4da018f4be0c9

libwvdrmengine/oemcrypto/ref/src/wvcrc32.h

@@ -0,0 +1,17 @@
+// 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.
+//
+// Compute CRC32 Checksum. Needed for verification of WV Keybox.
+//
+#ifndef WVCRC32_H_
+#define WVCRC32_H_
+
+#include <stdint.h>
+
+uint32_t wvcrc32(const uint8_t* p_begin, int i_count);
+
+// Convert to network byte order
+uint32_t wvcrc32n(const uint8_t* p_begin, int i_count);
+
+#endif  // WVCRC32_H_