Add chromeos namespace to the language options page and its friends.

chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h

Index: chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h
diff --git a/chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h b/chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h
index 246b689a4a739559d2d5eab66bc195dc327c3998..224fecc8e74e9ac0c464cedb49d5d407f13ed0ad 100644
--- a/chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h
+++ b/chrome/browser/chromeos/dom_ui/language_chewing_options_handler.h
@@ -10,6 +10,8 @@
 
 class DictionaryValue;
 
+namespace chromeos {
+
 // Chewing options page UI handler.
 class LanguageChewingOptionsHandler : public OptionsPageUIHandler {
  public:
@@ -23,4 +25,6 @@ class LanguageChewingOptionsHandler : public OptionsPageUIHandler {
   DISALLOW_COPY_AND_ASSIGN(LanguageChewingOptionsHandler);
 };
 
+}  // namespace chromeos
+
 #endif  // CHROME_BROWSER_CHROMEOS_DOM_UI_LANGUAGE_CHEWING_OPTIONS_HANDLER_H_