[Sync] Move //sync to //components/sync.

sync/protocol/theme_specifics.proto

-// Copyright (c) 2012 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.
-//
-// Sync protocol datatype extension for themes.
-
-// Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
-// any fields in this file.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-option retain_unknown_fields = true;
-
-package sync_pb;
-
-// Properties of theme sync objects.
-message ThemeSpecifics {
-  // If set, we're using a custom theme and all custom_* fields should be
-  // present.  If not set, we use the default or system theme (see below)
-  // and all custom_* fields should be omitted.
-  optional bool use_custom_theme = 1;
-  // This field is only set (i.e., not cleared) on platforms that have
-  // a distinction between the system theme and the default theme, but
-  // other platforms must be careful to pass through the set state (not
-  // just the value) of this flag.
-  //
-  // If true, we use the system theme by default (i.e., when we don't use
-  // a custom theme) for platforms that make a distinction between the
-  // default theme and the system theme.  Has no effect if use_custom_theme
-  // is set.
-  optional bool use_system_theme_by_default = 2;
-
-  // Custom-theme-specific fields.
-  optional string custom_theme_name = 3;
-  optional string custom_theme_id = 4;
-  optional string custom_theme_update_url = 5;
-}
-