Adds the input method private API to allow the component IME extension to change the XKB layout.

chrome/browser/chromeos/extensions/input_method_api.cc

Index: chrome/browser/chromeos/extensions/input_method_api.cc
diff --git a/chrome/browser/chromeos/extensions/input_method_api.cc b/chrome/browser/chromeos/extensions/input_method_api.cc
index 28d1811bd5ac832a74f80cf3c56018f33b949508..11683fde3677385087116ee534d44e0789c6d1f7 100644
--- a/chrome/browser/chromeos/extensions/input_method_api.cc
+++ b/chrome/browser/chromeos/extensions/input_method_api.cc
@@ -26,6 +26,7 @@
 #include "extensions/browser/extension_function_registry.h"
 #include "extensions/browser/extension_system.h"
 #include "ui/base/ime/chromeos/extension_ime_util.h"
+#include "ui/base/ime/chromeos/ime_keyboard.h"
 #include "ui/base/ime/chromeos/input_method_descriptor.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #include "ui/keyboard/keyboard_util.h"
@@ -34,6 +35,7 @@ namespace AddWordToDictionary =
     extensions::api::input_method_private::AddWordToDictionary;
 namespace SetCurrentInputMethod =
     extensions::api::input_method_private::SetCurrentInputMethod;
+namespace SetXkbLayout = extensions::api::input_method_private::SetXkbLayout;
 namespace OnChanged = extensions::api::input_method_private::OnChanged;
 namespace OnDictionaryChanged =
     extensions::api::input_method_private::OnDictionaryChanged;
@@ -195,6 +197,21 @@ InputMethodPrivateGetEncryptSyncEnabledFunction::Run() {
 #endif
 }
 
+ExtensionFunction::ResponseAction
+InputMethodPrivateSetXkbLayoutFunction::Run() {
+#if !defined(OS_CHROMEOS)
+  EXTENSION_FUNCTION_VALIDATE(false);
+#else
+  scoped_ptr<SetXkbLayout::Params> params(SetXkbLayout::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+  chromeos::input_method::InputMethodManager* manager =
+      chromeos::input_method::InputMethodManager::Get();
+  chromeos::input_method::ImeKeyboard* keyboard = manager->GetImeKeyboard();
+  keyboard->SetCurrentKeyboardLayoutByName(params->xkb_name);

[Seigo Nonaka, 2016/01/20 09:12:47]

just FYI

Please be careful. The passed string will be used for constructing arguments of
the new process.

I think it is safe now since this API is private and the passed argument is
sanitized. Please don't expose this API to public as this is.

[Shu Chen, 2016/01/20 09:17:22]

Thanks for reminding. This API will remain private.

Btw, SetCurrentKeyboardLayoutByName() won't cause new process as X11 has been
removed from Chrome OS.

+  return RespondNow(NoArguments());
+#endif
+}
+
 InputMethodAPI::InputMethodAPI(content::BrowserContext* context)
     : context_(context) {
   EventRouter::Get(context_)->RegisterObserver(this, OnChanged::kEventName);