Adds HotwordPrivate API for integrating the hotword feature to AppLauncher

chrome/common/extensions/api/hotword_private.idl

 // 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.
 
 // The <code>chrome.hotwordPrivate</code> API allows extensions to access and
 // mutate the preference for enabling hotword search. It also provides
 // information on whether the hotword search is available. This API provides an
 // event interface to transmit to the extension a signal that the preference fo
 // hotword search has change.
 //
@@ skipping 10 matching lines @@
     boolean enabled;
 
     // Whether the hotword extension is available to be enabled
     boolean available;
 
     // Whether the sound of "Ok, Google" plus a few seconds before is sent
     // back to Google.
     boolean audioLoggingEnabled;
   };
 
+  // The type of the recognized hotword. Right now it only has 'search' but
+  // could be expanded to other types of actions in the future.
+  enum HotwordType { search };
+
   callback GenericDoneCallback = void ();
   callback StatusDetailsCallback = void(StatusDetails result);
 
   interface Functions {
     // Sets the current enabled state of hotword search.
     // True: enable hotword search. False: disable hotword search.
     static void setEnabled(boolean state, optional GenericDoneCallback callback);
 
     // Retrieves the current state of hotword search.
     // The result is put into a StatusDetails object.
     static void getStatus(StatusDetailsCallback callback);
 
     // Sets the current enabled state of audio logging in the extension.
     // True: logging enabled. False: no logging.
     static void setAudioLoggingEnabled(boolean state, optional GenericDoneCallback callback);
+
+    // Sets the current hotword session state for the browser's special request.

[rpetterson, 2014/05/02 19:13:16]

What does the "browser's special request" mean?

[Jun Mukai, 2014/05/02 22:18:57]

that is browser-requested hotword session. updated the comment.

+    // See onHotwordSessionRequested() and onHotwordSessionStopped().
+    static void setHotwordSessionState(boolean started, optional GenericDoneCallback callback);
+
+    // Notifies the hotword is recognized for the browser-requested hotword

[rpetterson, 2014/05/02 19:13:16]

If I'm understanding correctly, this function is used to pass along the fact
that a hotword ("ok google," etc.) was recognized by the nacl component and we
want to pass that information along to Chrome. Perhaps reword:
// Notifies that a hotword has been recognized in the browser-requested hotword
session.

[Jun Mukai, 2014/05/02 22:18:57]

Done.

+    // session.
+    static void notifyHotwordRecognition(HotwordType type, optional GenericDoneCallback callback);
   };
 
   interface Events {
     // Fired when the hotword search enabled preference is changed.
     static void onEnabledChanged();
+
+    // Fired when the browser wants to start a hotword session.
+    static void onHotwordSessionRequested();
+
+    // Fired when the browser wants to stop the requested hotword session.
+    static void onHotwordSessionStopped();
   };
 };