Adds extension APIs of events on changing volume.

chrome/browser/accessibility_events.cc

 // Copyright (c) 2011 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/accessibility_events.h"
 
 #include "base/values.h"
 
 #include "chrome/browser/extensions/extension_accessibility_api_constants.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 170 matching lines @@
   return keys::kTypeListBox;
 }
 
 void AccessibilityListBoxInfo::SerializeToDict(DictionaryValue *dict) const {
   AccessibilityControlInfo::SerializeToDict(dict);
   dict->SetString(keys::kValueKey, value_);
   dict->SetInteger(keys::kItemIndexKey, item_index_);
   dict->SetInteger(keys::kItemCountKey, item_count_);
 }
 
+AccessibilityVolumeInfo::AccessibilityVolumeInfo(Profile* profile,
+                                                 double volume,
+                                                 bool is_mute)
+    : AccessibilityControlInfo(profile, "volume"),
+      volume_(volume),
+      is_mute_(is_mute) {
+}
+
+const char* AccessibilityVolumeInfo::type() const {
+  return keys::kTypeVolume;
+}
+
+void AccessibilityVolumeInfo::SerializeToDict(DictionaryValue *dict) const {
+  AccessibilityControlInfo::SerializeToDict(dict);
+  dict->SetDouble(keys::kVolumeKey, volume_);
+  dict->SetBoolean(keys::kIsVolumeMuteKey, is_mute_);
+}
+
 AccessibilityMenuInfo::AccessibilityMenuInfo(Profile* profile,
                                              const std::string& menu_name)
     : AccessibilityControlInfo(profile, menu_name) {
 }
 
 const char* AccessibilityMenuInfo::type() const {
   return keys::kTypeMenu;
 }
 
 AccessibilityMenuItemInfo::AccessibilityMenuItemInfo(Profile* profile,
@@ skipping 10 matching lines @@
 const char* AccessibilityMenuItemInfo::type() const {
   return keys::kTypeMenuItem;
 }
 
 void AccessibilityMenuItemInfo::SerializeToDict(DictionaryValue *dict) const {
   AccessibilityControlInfo::SerializeToDict(dict);
   dict->SetBoolean(keys::kHasSubmenuKey, has_submenu_);
   dict->SetInteger(keys::kItemIndexKey, item_index_);
   dict->SetInteger(keys::kItemCountKey, item_count_);
 }