Updates the mic icon status based on the device's audio state.

chrome/browser/ui/app_list/search/search_resource_manager.cc

 // Copyright 2014 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/app_list/search/search_resource_manager.h"
 
 #include "chrome/browser/ui/app_list/start_page_service.h"
 #include "grit/components_scaled_resources.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/app_list/search_box_model.h"
 #include "ui/app_list/speech_ui_model.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace app_list {
 
+namespace {
+
+scoped_ptr<SearchBoxModel::SpeechButtonProperty> CreateNewProperty(
+    SpeechRecognitionState state) {
+  if (state == SPEECH_RECOGNITION_OFF)
+    return nullptr;
+
+  ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
+  return make_scoped_ptr(new SearchBoxModel::SpeechButtonProperty(
+      *bundle.GetImageSkiaNamed(IDR_OMNIBOX_MIC_SEARCH),
+      l10n_util::GetStringUTF16(IDS_APP_LIST_HOTWORD_LISTENING),
+      *bundle.GetImageSkiaNamed(IDR_APP_LIST_MIC_HOTWORD_OFF),
+      l10n_util::GetStringUTF16(IDS_APP_LIST_START_SPEECH_RECOGNITION)));
+}
+
+}  // namespace
+
 SearchResourceManager::SearchResourceManager(Profile* profile,
                                              SearchBoxModel* search_box,
                                              SpeechUIModel* speech_ui)
     : search_box_(search_box),
       speech_ui_(speech_ui) {
   speech_ui_->AddObserver(this);
 
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   search_box_->SetIcon(*bundle.GetImageSkiaNamed(IDR_OMNIBOX_SEARCH));
   StartPageService* service = StartPageService::Get(profile);
   if (service && service->GetSpeechRecognitionContents()) {
     search_box_->SetSpeechRecognitionButton(
-        scoped_ptr<SearchBoxModel::SpeechButtonProperty>(
-            new SearchBoxModel::SpeechButtonProperty(
-                *bundle.GetImageSkiaNamed(IDR_OMNIBOX_MIC_SEARCH),
-                l10n_util::GetStringUTF16(
-                    IDS_APP_LIST_HOTWORD_LISTENING),
-                *bundle.GetImageSkiaNamed(IDR_APP_LIST_MIC_HOTWORD_OFF),
-                l10n_util::GetStringUTF16(
-                    IDS_APP_LIST_START_SPEECH_RECOGNITION))));
+        CreateNewProperty(service->state()));
   }

[tapted, 2014/11/26 02:05:59]

it looks like the whole if block above is redundant, since the call to
OnSpeechRecognitionStateChanged below calls
search_box_->SetSpeechRecognitionButton(..) unconditionally

[Jun Mukai, 2014/11/26 23:29:51]

Done.

   OnSpeechRecognitionStateChanged(speech_ui_->state());
 }
 
 SearchResourceManager::~SearchResourceManager() {
   speech_ui_->RemoveObserver(this);
 }
 
 void SearchResourceManager::OnSpeechRecognitionStateChanged(
     SpeechRecognitionState new_state) {
   search_box_->SetHintText(l10n_util::GetStringUTF16(
       (new_state == SPEECH_RECOGNITION_HOTWORD_LISTENING) ?
       IDS_SEARCH_BOX_HOTWORD_HINT : IDS_SEARCH_BOX_HINT));
+  search_box_->SetSpeechRecognitionButton(CreateNewProperty(new_state));
 }
 
 }  // namespace app_list