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/oemcrypto_nonce_table.cpp

@@ -0,0 +1,69 @@
+// 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.
+//
+//  Ref implementation of OEMCrypto APIs
+//
+#include "oemcrypto_nonce_table.h"
+
+namespace wvoec_ref {
+
+void NonceTable::AddNonce(uint32_t nonce) {
+  int new_slot = -1;
+  int oldest_slot = -1;
+
+  // Flush any nonces that have been checked but not flushed.
+  // After flush, nonces will be either valid or invalid.
+  Flush();
+
+  for (int i = 0; i < kTableSize; ++i) {
+    // Increase age of all valid nonces.
+    if (kNTStateValid == state_[i]) {
+      ++age_[i];
+      if (-1 == oldest_slot) {
+        oldest_slot = i;
+      } else {
+        if (age_[i] > age_[oldest_slot]) {
+          oldest_slot = i;
+        }
+      }
+    } else {
+      if (-1 == new_slot) {
+        age_[i] = 0;
+        nonces_[i] = nonce;
+        state_[i] = kNTStateValid;
+        new_slot = i;
+      }
+    }
+  }
+  if (-1 == new_slot) {
+    // reuse oldest
+    // assert (oldest_slot != -1)
+    int i = oldest_slot;
+    age_[i] = 0;
+    nonces_[i] = nonce;
+    state_[i] = kNTStateValid;
+  }
+}
+
+bool NonceTable::CheckNonce(uint32_t nonce) {
+  for (int i = 0; i < kTableSize; ++i) {
+    if (kNTStateInvalid != state_[i]) {
+      if (nonce == nonces_[i]) {
+        state_[i] = kNTStateFlushPending;
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+void NonceTable::Flush() {
+  for (int i = 0; i < kTableSize; ++i) {
+    if (kNTStateFlushPending == state_[i]) {
+      state_[i] = kNTStateInvalid;
+    }
+  }
+}
+
+}  // namespace wvoec_ref