[Hotword] Reverse the experimental flag so that it is on by default.

chrome/browser/search/hotword_service.cc

 // Copyright 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.
 
 #include "chrome/browser/search/hotword_service.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/i18n/case_conversion.h"
@@ skipping 257 matching lines @@
 // static
 bool HotwordService::IsExperimentalHotwordingEnabled() {
   std::string group = base::FieldTrialList::FindFullName(
       hotword_internal::kHotwordFieldTrialName);
   if (!group.empty() &&
       group == hotword_internal::kHotwordFieldTrialExperimentalGroupName) {
     return true;
   }
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
-  return command_line->HasSwitch(switches::kEnableExperimentalHotwording);
+  return !command_line->HasSwitch(switches::kDisableExperimentalHotwording);
 }
 
 #if defined(OS_CHROMEOS)
 class HotwordService::HotwordUserSessionStateObserver
     : public user_manager::UserManager::UserSessionStateObserver {
  public:
   explicit HotwordUserSessionStateObserver(HotwordService* service)
       : service_(service) {}
 
   // Overridden from UserSessionStateObserver:
@@ skipping 525 matching lines @@
   HotwordPrivateEventService* event_service =
       BrowserContextKeyedAPIFactory<HotwordPrivateEventService>::Get(profile_);
   // "enabled" isn't being changed, but piggy-back off the notification anyway.
   if (event_service)
     event_service->OnEnabledChanged(prefs::kHotwordSearchEnabled);
 }
 
 bool HotwordService::UserIsActive() {
   return profile_ == ProfileManager::GetActiveUserProfile();
 }