Move crypto_helpers from sync to crypto

crypto_helpers only depends on resources in base and is used by sync and
password_manager.

BUG=
TEST=


Review URL: http://codereview.chromium.org/6873156

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84223 0039d316-1c4b-4281-b951-d872f2087c98

• base/rand_util.cc[diff]
• base/rand_util.h[diff]
• base/rand_util_unittest.cc[diff]
• chrome/browser/password_manager/encryptor_password_mac.mm[diff]
• chrome/browser/sync/engine/syncapi.cc[diff]
• chrome/browser/sync/syncable/directory_backing_store.cc[diff]
• chrome/browser/sync/syncable/syncable.cc[diff]
• chrome/browser/sync/util/crypto_helpers.cc[Deleted - diff]
• chrome/browser/sync/util/crypto_helpers.h[Deleted - diff]
• chrome/browser/sync/util/crypto_helpers_unittest.cc[Deleted - diff]
• chrome/browser/sync/util/user_settings.cc[diff]
• chrome/browser/sync/util/user_settings_win.cc[diff]
• chrome/chrome.gyp[diff]
• chrome/chrome_common.gypi[diff]
• chrome/chrome_tests.gypi[diff]
• chrome/common/random.cc[Added - diff]
• chrome/common/random.h[Added - diff]
• chrome/common/random_unittest.cc[Added - diff]
• ppapi/shared_impl/crypto_impl.cc[diff]
• webkit/glue/webkitclient_impl.cc[diff]