Fix domdistiller for new JS execution

components/dom_distiller/ios/distiller_page_ios.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 COMPONENTS_DOM_DISTILLER_IOS_DISTILLER_PAGE_IOS_H_
 #define COMPONENTS_DOM_DISTILLER_IOS_DISTILLER_PAGE_IOS_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 26 matching lines @@
   bool StringifyOutput() override;
   void DistillPageImpl(const GURL& url, const std::string& script) override;
 
  private:
   friend class DistillerWebStateObserver;
 
   // Called by |web_state_observer_| once the page has finished loading.
   void OnLoadURLDone(web::PageLoadCompletionStatus load_completion_status);
 
   // Called once the |script_| has been evaluated on the page.
-  void HandleJavaScriptResultString(NSString* result);
+  void HandleJavaScriptResult(id result);
+
+  // Converts result of WKWebView script evaluation to base::Value
+  std::unique_ptr<base::Value> ValueResultFromScriptResult(id wk_result);
 
   web::BrowserState* browser_state_;
   GURL url_;
   std::string script_;
   std::unique_ptr<ios::WebControllerProvider> provider_;
   std::unique_ptr<DistillerWebStateObserver> web_state_observer_;
   base::WeakPtrFactory<DistillerPageIOS> weak_ptr_factory_;
 };
 
 }  // namespace dom_distiller
 
 #endif  // COMPONENTS_DOM_DISTILLER_IOS_DISTILLER_PAGE_IOS_H_