WebUI: Add helper FireWebUIListener method on WebUIMessageHandler.

chrome/browser/ui/webui/settings/search_engines_handler.cc

 // Copyright 2016 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 "chrome/browser/ui/webui/settings/search_engines_handler.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 178 matching lines @@
       new base::DictionaryValue);
   search_engines_info->Set("defaults", base::WrapUnique(defaults.release()));
   search_engines_info->Set("others", base::WrapUnique(others.release()));
   search_engines_info->Set("extensions",
                            base::WrapUnique(extensions.release()));
   return search_engines_info;
 }
 
 void SearchEnginesHandler::OnModelChanged() {
   AllowJavascript();
-  CallJavascriptFunction("cr.webUIListenerCallback",
-                         base::Value("search-engines-changed"),
-                         *GetSearchEnginesList());
+  FireWebUIListener("search-engines-changed", *GetSearchEnginesList());
+
   // Google Now availability may have changed.
-  CallJavascriptFunction("cr.webUIListenerCallback",
-                         base::Value("google-now-availability-changed"),
-                         base::Value(IsGoogleNowAvailable(profile_)));
+  FireWebUIListener("google-now-availability-changed",
+                    base::Value(IsGoogleNowAvailable(profile_)));
 }
 
 void SearchEnginesHandler::OnItemsChanged(int start, int length) {
   OnModelChanged();
 }
 
 void SearchEnginesHandler::OnItemsAdded(int start, int length) {
   OnModelChanged();
 }
 
@@ skipping 291 matching lines @@
     bool success,
     bool logging_enabled) {
   if (success)
     status->SetBoolean(kHotwordSatusHistoryEnabled, logging_enabled);
   HotwordInfoComplete(callback_id.get(), *status);
 }
 
 void SearchEnginesHandler::HotwordInfoComplete(
     const base::Value* callback_id,
     const base::DictionaryValue& status) {
-  if (callback_id) {
+  if (callback_id)
     ResolveJavascriptCallback(*callback_id, status);
-  } else {
-    CallJavascriptFunction("cr.webUIListenerCallback",
-                           base::Value("hotword-info-update"), status);
-  }
+  else
+    FireWebUIListener("hotword-info-update", status);
 }
 
 void SearchEnginesHandler::SendHotwordInfo() {
   HandleGetHotwordInfo(nullptr);
 }
 
 void SearchEnginesHandler::HandleSetHotwordSearchEnabled(
     const base::ListValue* args) {
   CHECK_EQ(1U, args->GetSize());
   bool enabled;
@@ skipping 22 matching lines @@
     bool logging_enabled =
         profile_->GetPrefs()->GetBoolean(prefs::kHotwordAudioLoggingEnabled);
     launch_mode = logging_enabled ? HotwordService::HOTWORD_ONLY
                                   : HotwordService::HOTWORD_AND_AUDIO_HISTORY;
   }
   hotword_service->OptIntoHotwording(launch_mode);
   SendHotwordInfo();
 }
 
 }  // namespace settings