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..ed92efb292d46de63479b9f236595a0e3b2a46d0 100644
--- a/chrome/common/extensions/api/quick_unlock_private.idl
+++ b/chrome/common/extensions/api/quick_unlock_private.idl
@@ -19,8 +19,24 @@ namespace quickUnlockPrivate {
     PIN
   };
 
+  enum CredentialProblem {
+    TOO_SHORT,
+    TOO_LONG,
+    TOO_WEAK,
+    CONTAINS_NONDIGIT
+  };
+
+  dictionary CredentialCheck {
+    CredentialProblem[] errors;
+    CredentialProblem[] warnings;
+    long minLength;
+    // If |maxLength| is 0, there is no PIN max length.
+    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
@@ -31,6 +47,12 @@ 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.