Allow component IME extension use app.window and add 'ime' window type for app window

extensions/browser/app_window/app_window.cc

Index: extensions/browser/app_window/app_window.cc
diff --git a/extensions/browser/app_window/app_window.cc b/extensions/browser/app_window/app_window.cc
index 035b4e9ff663f3a0e98b27a9746ce4ab261febfd..a3289e4c1c166b84075b5af612157f7147b3f629 100644
--- a/extensions/browser/app_window/app_window.cc
+++ b/extensions/browser/app_window/app_window.cc
@@ -155,6 +155,7 @@ AppWindow::CreateParams::CreateParams()
       active_frame_color(SK_ColorBLACK),
       inactive_frame_color(SK_ColorBLACK),
       alpha_enabled(false),
+      is_ime_window(false),
       creator_process_id(0),
       state(ui::SHOW_STATE_DEFAULT),
       hidden(false),
@@ -238,7 +239,8 @@ AppWindow::AppWindow(BrowserContext* context,
       can_send_events_(false),
       is_hidden_(false),
       cached_always_on_top_(false),
-      requested_alpha_enabled_(false) {
+      requested_alpha_enabled_(false),
+      is_ime_window_(false) {
   ExtensionsBrowserClient* client = ExtensionsBrowserClient::Get();
   CHECK(!client->IsGuestSession(context) || context->IsOffTheRecord())
       << "Only off the record window may be opened in the guest mode.";
@@ -275,6 +277,7 @@ void AppWindow::Init(const GURL& url,
     new_params.always_on_top = false;
 
   requested_alpha_enabled_ = new_params.alpha_enabled;
+  is_ime_window_ = new_params.is_ime_window;
 
   AppsClient* apps_client = AppsClient::Get();
   native_app_window_.reset(
@@ -724,6 +727,7 @@ void AppWindow::GetSerializedState(base::DictionaryValue* properties) const {
   properties->SetBoolean(
       "alphaEnabled",
       requested_alpha_enabled_ && native_app_window_->CanHaveAlphaEnabled());
+  properties->SetBoolean("isImeWindow", is_ime_window_);
 
   // These properties are undocumented and are to enable testing. Alpha is
   // removed to