Move crypto_helpers from sync to base

chrome/browser/sync/syncable/directory_backing_store.cc

Index: chrome/browser/sync/syncable/directory_backing_store.cc
diff --git a/chrome/browser/sync/syncable/directory_backing_store.cc b/chrome/browser/sync/syncable/directory_backing_store.cc
index 7f5721e64e30d9a345c4dc7bc08795a924868729..decce16e2a7440b2a3e2aaf28f1df9c42e9d792d 100644
--- a/chrome/browser/sync/syncable/directory_backing_store.cc
+++ b/chrome/browser/sync/syncable/directory_backing_store.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -24,8 +24,8 @@
 #include "chrome/browser/sync/protocol/sync.pb.h"
 #include "chrome/browser/sync/syncable/syncable-inl.h"
 #include "chrome/browser/sync/syncable/syncable_columns.h"
-#include "chrome/browser/sync/util/crypto_helpers.h"
 #include "chrome/common/sqlite_utils.h"
+#include "crypto/random.h"
 #include "third_party/sqlite/sqlite3.h"
 
 // Sometimes threads contend on the DB lock itself, especially when one thread
@@ -61,7 +61,7 @@ int ExecQuery(sqlite3* dbhandle, const char* query) {
 }
 
 string GenerateCacheGUID() {
-  return Generate128BitRandomHexString();
+  return Generate128BitRandomBase64String();
 }
 
 }  // namespace