Adds HotwordPrivate API for integrating the hotword feature to AppLauncher

chrome/common/extensions/api/hotword_private.idl

Index: chrome/common/extensions/api/hotword_private.idl
diff --git a/chrome/common/extensions/api/hotword_private.idl b/chrome/common/extensions/api/hotword_private.idl
index 7e1a60b89cb99c5b556b398ecf888398c57889f4..fbf3efb039bbf313b8c5e9b079634905230dee72 100644
--- a/chrome/common/extensions/api/hotword_private.idl
+++ b/chrome/common/extensions/api/hotword_private.idl
@@ -28,6 +28,10 @@
     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);
 
@@ -43,10 +47,24 @@
     // 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();
   };
 };