We should switch the keyboard layout to the layout the user set according to

chrome/browser/chromeos/input_method/input_method_manager_impl_ll.h

+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_MANAGER_IMPL_LL_H_
+#define CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_MANAGER_IMPL_LL_H_
+
+// "Latin Layout" checker: checks if given keyboard layout is "Full Latin Input"
+
+#include <string>
+#include <vector>
+
+#include "base/strings/string_util.h"
+
+namespace chromeos {
+namespace input_method {
+
+class TwoLetterLanguageCode {
+ public:
+  TwoLetterLanguageCode() : val(0) {}
+  explicit TwoLetterLanguageCode(const char* lang)
+      : val(base::ToLowerASCII(lang[0]) * 256 + base::ToLowerASCII(lang[1])) {}
+
+  bool operator<(const TwoLetterLanguageCode& r) const { return val < r.val; }
+  bool operator!=(const TwoLetterLanguageCode& r) const { return val != r.val; }
+
+ private:
+  uint16_t val;
+};
+
+// To keep index small, sizeof(TwoLetterLanguageCode2KBDList) = 4.
+class TwoLetterLanguageCode2KBDList {
+ public:
+  TwoLetterLanguageCode2KBDList() : index(0) {}
+  TwoLetterLanguageCode2KBDList(const char* l, const uint16_t i)
+      : lang(l), index(i) {}
+
+  bool operator<(const TwoLetterLanguageCode2KBDList& r) const {
+    return lang < r.lang;
+  }
+  bool operator<(const TwoLetterLanguageCode& r) const { return lang < r; }
+
+  TwoLetterLanguageCode lang;
+
+  // index in kHasLatinKeyboardLanguageList[]
+  uint16_t index;
+};
+
+// For fast lookup "whether this language and layout are among listed in
+// kHasLatinKeyboardLanguageList[] or not".
+class FullLatinKeyboardLayoutChecker {
+ public:
+  FullLatinKeyboardLayoutChecker();
+  ~FullLatinKeyboardLayoutChecker();
+
+  bool IsFullLatinKeyboard(const std::string& layout,
+                           const std::string& lang) const;
+
+ private:
+  // Sorted vector for fast lookup.
+  std::vector<TwoLetterLanguageCode2KBDList> full_latin_keyboard_languages_;
+};
+
+}  // namespace input_method
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_MANAGER_IMPL_LL_H_