[Extenisons Bindings] Don't throw unchecked errors; add console errors

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"
 #include "base/macros.h"
 #include "v8/include/v8.h"
 
 namespace extensions {
 
 // Handles creating and clearing a 'lastError' property to hold the last error
 // set by an extension API function.
 class APILastError {
  public:
   // Returns the object the 'lastError' property should be exposed on for the
   // given context.
   using GetParent =
       base::Callback<v8::Local<v8::Object>(v8::Local<v8::Context>)>;
+  // Adds an error message to the context's console.
+  using AddConsoleError =
+      base::Callback<void(v8::Local<v8::Context>, const std::string& error)>;
 
-  explicit APILastError(const GetParent& get_parent);
+  APILastError(const GetParent& get_parent,
+               const AddConsoleError& add_console_error);
   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_;
 
+  AddConsoleError add_console_error_;
+
   DISALLOW_COPY_AND_ASSIGN(APILastError);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_LAST_ERROR_H_