Adds extension APIs of events on changing volume.

chrome/browser/extensions/extension_accessibility_api.cc

Index: chrome/browser/extensions/extension_accessibility_api.cc
diff --git a/chrome/browser/extensions/extension_accessibility_api.cc b/chrome/browser/extensions/extension_accessibility_api.cc
index f63234244ef28a7c75b38156ea18da84da7f8f8f..80dde8969d4825452fbfeca81f52f75f4025dfc1 100644
--- a/chrome/browser/extensions/extension_accessibility_api.cc
+++ b/chrome/browser/extensions/extension_accessibility_api.cc
@@ -25,7 +25,7 @@ namespace keys = extension_accessibility_api_constants;
 // Returns the AccessibilityControlInfo serialized into a JSON string,
 // consisting of an array of a single object of type AccessibilityObject,
 // as defined in the accessibility extension api's json schema.
-std::string ControlInfoToJsonString(const AccessibilityControlInfo* info) {
+std::string ControlInfoToJsonString(const AccessibilityEventInfo* info) {
   ListValue args;
   DictionaryValue* dict = new DictionaryValue();
   info->SerializeToDict(dict);
@@ -73,6 +73,9 @@ void ExtensionAccessibilityEventRouter::ObserveProfile(Profile* profile) {
     registrar_.Add(this,
                    chrome::NOTIFICATION_ACCESSIBILITY_MENU_CLOSED,
                    NotificationService::AllSources());
+    registrar_.Add(this,
+                   chrome::NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED,
+                   NotificationService::AllSources());
   }
 }
 
@@ -102,6 +105,9 @@ void ExtensionAccessibilityEventRouter::Observe(
     case chrome::NOTIFICATION_ACCESSIBILITY_MENU_CLOSED:
       OnMenuClosed(Details<const AccessibilityMenuInfo>(details).ptr());
       break;
+    case chrome::NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED:
+      OnVolumeChanged(Details<const AccessibilityVolumeInfo>(details).ptr());
+      break;
     default:
       NOTREACHED();
   }
@@ -180,6 +186,12 @@ void ExtensionAccessibilityEventRouter::OnMenuClosed(
   DispatchEvent(info->profile(), keys::kOnMenuClosed, json_args);
 }
 
+void ExtensionAccessibilityEventRouter::OnVolumeChanged(
+    const AccessibilityVolumeInfo* info) {
+  std::string json_args = ControlInfoToJsonString(info);
+  DispatchEvent(info->profile(), keys::kOnVolumeChanged, json_args);
+}
+
 void ExtensionAccessibilityEventRouter::DispatchEvent(
     Profile* profile,
     const char* event_name,