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..02c1842bcaf836960503259d92bca74503c41098 100644
--- a/chrome/common/extensions/api/quick_unlock_private.idl
+++ b/chrome/common/extensions/api/quick_unlock_private.idl
@@ -19,8 +19,22 @@ namespace quickUnlockPrivate {
     PIN
   };
 
+  enum CredentialProblem {
+    TOO_SHORT,
+    TOO_LONG,
+    TOO_WEAK
+  };
+
+  dictionary CredentialCheck {
+    CredentialProblem[] problems;
+    long? minLength;
+    long? maxLength;
+    boolean? allowWeakPins;

[jdufault, 2016/10/14 21:15:53]

I think this API will be more general and flexible if instead of exposing just
|problems|, we split it up into |errors| and |warnings|. 

This means that the |allowWeakPins| will not be needed.

For example, if in the future we add a new problem type, PREVIOUSLY_USED, then
we would have to add another credential boolean allowReusedPin if we did not
have the errors/warnings split.

[sammiequon, 2016/10/31 18:49:34]

Done.

+  };
+
   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
@@ -31,6 +45,12 @@ namespace quickUnlockPrivate {
     // 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.