Extract Extension IME related utility.

chromeos/ime/extension_ime_util.cc

+// Copyright 2013 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.
+
+#include "chromeos/ime/extension_ime_util.h"
+
+#include "base/string_util.h"
+
+namespace chromeos {
+namespace {
+const char* kExtensionIMEPrefix = "_ext_ime_";
+}  // namespace
+
+namespace extension_ime_util {
+std::string GetInputMethodID(const std::string& extension_id,
+                             const std::string& engine_id) {
+  DCHECK(!extension_id.empty());
+  DCHECK(!engine_id.empty());
+  return kExtensionIMEPrefix + extension_id + engine_id;
+}
+
+bool IsExtensionIME(const std::string& input_method_id) {
+  return StartsWithASCII(input_method_id,
+                         kExtensionIMEPrefix,
+                         true);  // Case sensitive.
+}
+
+}  // namespace extension_ime_util
+}  // namespace chromeos