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

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
index c3121beffcaf4e61c5d7148737a66a8e72b6f317..3e59a2e115ccaca4ee8944d6b548219870570935 100644
--- a/chrome/common/extensions/api/quick_unlock_private.idl
+++ b/chrome/common/extensions/api/quick_unlock_private.idl
@@ -19,8 +19,17 @@ namespace quickUnlockPrivate {
     PIN
   };
 
+  enum PinState {
+    GOOD,
+    SHORTER_THAN_MIN,
+    LONGER_THAN_MAX,
+    ALL_SAME_NUM,
+    INCREASING
+  };
+
   callback BooleanResultCallback = void (boolean value);
   callback ModesCallback = void (QuickUnlockMode[] modes);
+  callback PinStatesCallback = void (PinState state);
 
   interface Functions {
     // Returns the set of quick unlock modes that are available for the user to
@@ -31,6 +40,11 @@ namespace quickUnlockPrivate {
     // the lock screen.
     static void getActiveModes(ModesCallback onComplete);
 
+    // Returns whether the pin can be used or if there is issue with the choice
+    // of pin.
+    static void getUsablePin(DOMString attemptedPassword,

[jdufault, 2016/09/29 19:36:52]

Note the difference between how password and credential are used in this file.

This API needs to account for two additional things:

- Adding a new quick unlock mode
- Exposing information to the user (such as minimum length).

We should reach out to UI folks and decide if we need to expose specific
information, because that will change the shape of the API. For example, it may
be okay to say "This PIN is too short" instead of "Enter a PIN between 4 and 6
digits".

What about something along these lines? We could drop CredentialRequirement if
we don't need the specific policy information.

  enum CredentialRequirementFailure {
    TOO_SHORT,
    TOO_LONG,
    TOO_WEAK
  };
  
  dictionary CredentialRequirement {
    CredentialRequirementFailure[] failures;
    Number? minLength;
    Number? maxLength;
  };

  callback CredentialRequirementCallback =
      void (CredentialRequirement requirement);

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

[sammiequon, 2016/09/30 00:35:08]

Done.

+                             PinStatesCallback 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.