[Extensions Bindings] Add lastError utilities to APIBindingJSUtil

extensions/renderer/api_last_error.h

 // Copyright 2017 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 EXTENSIONS_RENDERER_API_LAST_ERROR_H_
 #define EXTENSIONS_RENDERER_API_LAST_ERROR_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 15 matching lines @@
   APILastError(APILastError&& other);
   ~APILastError();
 
   // Sets the last error for the given |context| to |error|.
   void SetError(v8::Local<v8::Context> context, const std::string& error);
 
   // Clears the last error in the given |context|. If |report_if_unchecked| is
   // true and the developer didn't check the error, this throws an exception.
   void ClearError(v8::Local<v8::Context> context, bool report_if_unchecked);
 
+  // Returns true if the given context has an active error.
+  bool HasError(v8::Local<v8::Context> context);
+
  private:
   GetParent get_parent_;
 
   DISALLOW_COPY_AND_ASSIGN(APILastError);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_LAST_ERROR_H_