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

chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h

Index: chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h
diff --git a/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h b/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h
index 65e79fa1a08ee2ccb769c385473995241e37e1ee..6282912838067a7cfbde7e4ab381da8b3d4a8592 100644
--- a/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h
+++ b/chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h
@@ -56,6 +56,27 @@ class QuickUnlockPrivateGetActiveModesFunction
   DISALLOW_COPY_AND_ASSIGN(QuickUnlockPrivateGetActiveModesFunction);
 };
 
+class QuickUnlockPrivateIsCredentialUsableFunction
+    : public UIThreadExtensionFunction {
+ public:
+  QuickUnlockPrivateIsCredentialUsableFunction();
+  DECLARE_EXTENSION_FUNCTION("quickUnlockPrivate.isCredentialUsable",
+                             QUICKUNLOCKPRIVATE_ISCREDENTIALUSABLE);
+
+ protected:
+  ~QuickUnlockPrivateIsCredentialUsableFunction() override;
+
+  // ExtensionFunction overrides.
+  ResponseAction Run() override;
+
+ private:
+  ChromeExtensionFunctionDetails chrome_details_;
+  std::unique_ptr<api::quick_unlock_private::IsCredentialUsable::Params>
+      params_;
+
+  DISALLOW_COPY_AND_ASSIGN(QuickUnlockPrivateIsCredentialUsableFunction);
+};
+
 class QuickUnlockPrivateSetModesFunction : public UIThreadExtensionFunction,
                                            public chromeos::AuthStatusConsumer {
  public: