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 CredentialRequirementFailure {
+    TOO_SHORT,
+    TOO_LONG,
+    TOO_WEAK
+  };
+
+  dictionary CredentialRequirement {
+    CredentialRequirementFailure[] failures;
+    long? minLength;
+    long? maxLength;
+    boolean? allowEasyPins;

[jdufault, 2016/10/04 22:57:28]

Why does the UI need to know the policy value for allowing weak pins?

[sammiequon, 2016/10/05 19:48:11]

I thought they will display a warning instead of error if weak pins are not
allowed.

[jdufault, 2016/10/05 21:47:37]

This means that some of the failures are not actually failures. That's very
confusing. Maybe we should:

- rename CredentialRequirementFailure to CredentialProblem
- add a CredentialProblem[] warnings entry to CredentialRequirement
- CredentialCheck is probably a better name for CredentialRequirement as well.
- Maybe checkCredential instead of isCredentialUsable as well?

[sammiequon, 2016/10/14 20:58:53]

Done.

+  };
+
   callback BooleanResultCallback = void (boolean value);
   callback ModesCallback = void (QuickUnlockMode[] modes);
+  callback CredentialRequirementCallback =
+      void (CredentialRequirement requirement);
 
   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);
 
+    // Returns a set of problems if any with the give mode and credential.

[jdufault, 2016/10/04 22:57:28]

What about:

// Checks if the given credential can be used for the given unlock mode.
Enterprise policy can change credential requirements.

[sammiequon, 2016/10/05 19:48:11]

Done.

+    static void isCredentialUsable(QuickUnlockMode mode,
+                                   DOMString credential,
+                                   CredentialRequirementCallback 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);
   };
 };