Implement the private API for quick unlock.

chrome/common/extensions/api/quick_unlock_private.idl

Index: chrome/common/extensions/api/quick_unlock_private.idl
diff --git a/chrome/common/extensions/api/quick_unlock_private.idl b/chrome/common/extensions/api/quick_unlock_private.idl
new file mode 100644
index 0000000000000000000000000000000000000000..6bcadc44f136cd342e33440dc61cade156f0ffda
--- /dev/null
+++ b/chrome/common/extensions/api/quick_unlock_private.idl
@@ -0,0 +1,49 @@
+// Copyright 2016 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.
+
+// Use the <code>chrome.quickUnlockPrivate</code> API to change the active quick
+// unlock modes and to change their respective credentials.
+//
+// Quick unlock only supports unlocking an account that has already been signed
+// in.
+//
+// The quick unlock authentication facilities are not available through this
+// API; they are built directly into the lock screen.
+
+[platforms=("chromeos"),
+ implemented_in="chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h"]
+namespace quickUnlockPrivate {
+  // TODO: Add more quick unlock modes, such as a pattern unlock.
+  enum QuickUnlockMode {
+    PIN
+  };
+
+  callback BooleanResultCallback = void (boolean value);
+  callback ModesCallback = void (QuickUnlockMode[] modes);
+
+  interface Functions {
+    // Returns the set of quick unlock modes that are available for the user to
+    // use. Some quick unlock modes may be disabled by policy.
+    static void getAvailableModes(ModesCallback onComplete);
+
+    // Returns the quick unlock modes that are currently enabled and usable on
+    // the lock screen.
+    static void getActiveModes(ModesCallback onComplete);
+
+    // Update the set of quick unlock modes that are currently active/enabled.
+    // |accountPassword| is the password associated with the account (e.g. the
+    // GAIA password) and is required to change the quick unlock credentials.
+    // |modes| is the quick unlock modes that should be active. |credentials|
+    // contains the associated credential for each mode. To keep the credential
+    // the same for one of the modes, pass an empty string.

[Devlin, 2016/05/31 22:58:38]

add comments for each param, rather than a giant comment for the function.

[jdufault, 2016/06/01 00:07:36]

Done.

+    static void setModes(DOMString accountPassword,

[Devlin, 2016/05/31 22:58:38]

We pass a plaintext password?

[jdufault, 2016/06/01 00:07:36]

Yes; the password transformation happens on the C++ side.

+                         QuickUnlockMode[] modes, DOMString[] credentials,
+                         BooleanResultCallback onComplete);
+  };
+
+  interface Events {
+    // Called after the active set of quick unlock modes has changed.
+    static void onActiveModesChanged(QuickUnlockMode[] newModes);
+  };
+};