cros: Added a new function to quick unlock api for checking unfinished pins.

chrome/common/extensions/api/quick_unlock_private.idl

 // 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(jdufault): Add more quick unlock modes, such as a pattern unlock.
   enum QuickUnlockMode {
     PIN
   };
 
+  enum CredentialProblem {
+    TOO_SHORT,
+    TOO_LONG,
+    TOO_WEAK
+  };
+
+  dictionary CredentialCheck {
+    CredentialProblem[] errors;
+    CredentialProblem[] warnings;
+    long? minLength;
+    long? maxLength;
+  };
+
   callback BooleanResultCallback = void (boolean value);
   callback ModesCallback = void (QuickUnlockMode[] modes);
+  callback CredentialCheckCallback = void (CredentialCheck check);
 
   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);
 
+    // Checks if the given credential can be used for the given unlock mode.
+    // Enterprise policy can change credential requirements.
+    static void checkCredential(QuickUnlockMode mode,
+                                DOMString credential,
+                                CredentialCheckCallback onComplete);
+
     // Update the set of quick unlock modes that are currently active/enabled.
     // |accountPassword|: The password associated with the account (e.g. the
     // GAIA password). This is required to change the quick unlock credentials.
     // |modes|: The quick unlock modes that should be active.
     // |credentials|: The associated credential for each mode. To keep
     // the credential the same for the associated mode, pass an empty string.
     // |onComplete|: Called with true if the quick unlock state was updated,
     // false otherwise. The update is treated as a single atomic operation.
     static void setModes(DOMString accountPassword,
                          QuickUnlockMode[] modes, DOMString[] credentials,
                          BooleanResultCallback onComplete);
   };
 
   interface Events {
     // Called after the active set of quick unlock modes has changed.
     // |activeModes|: The set of quick unlock modes which are now active.
     static void onActiveModesChanged(QuickUnlockMode[] activeModes);
   };
 };