[Smart Lock] Add a private API to show an error bubble anchored to the Smart Lock app window.

chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_EASY_UNLOCK_PRIVATE_EASY_UNLOCK_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_EASY_UNLOCK_PRIVATE_EASY_UNLOCK_PRIVATE_API_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 329 matching lines @@
 
  private:
   ~EasyUnlockPrivateGetUserImageFunction() override;
 
   // SyncExtensionFunction:
   bool RunSync() override;
 
   DISALLOW_COPY_AND_ASSIGN(EasyUnlockPrivateGetUserImageFunction);
 };
 
+class EasyUnlockPrivateShowErrorBubbleFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("easyUnlockPrivate.showErrorBubble",
+                             EASYUNLOCKPRIVATE_SHOWERRORBUBBLE)
+  EasyUnlockPrivateShowErrorBubbleFunction();
+
+ private:
+  ~EasyUnlockPrivateShowErrorBubbleFunction() override;
+
+  // SyncExtensionFunction:
+  bool RunSync() override;
+
+  DISALLOW_COPY_AND_ASSIGN(EasyUnlockPrivateShowErrorBubbleFunction);
+};
+
 }  // namespace api
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_EASY_UNLOCK_PRIVATE_EASY_UNLOCK_PRIVATE_API_H_