[ios] Removed UIWebView JS evaluation code.

ios/web/public/web_state/js/crw_js_injection_evaluator.h

 // Copyright 2012 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 IOS_WEB_PUBLIC_WEB_STATE_JS_CRW_JS_INJECTION_EVALUATOR_H_
 #define IOS_WEB_PUBLIC_WEB_STATE_JS_CRW_JS_INJECTION_EVALUATOR_H_
 
 #import <Foundation/Foundation.h>
 
 #include "ios/web/public/web_view_type.h"
 
 // The type of the completion handler block that is called from
 // |evaluateJavaScript:completionHandler|
 namespace web {
 typedef void (^JavaScriptCompletion)(NSString*, NSError*);
 }
 
 @protocol CRWJSInjectionEvaluator
 
 // Evaluates the supplied JavaScript in the WebView. Calls |completionHandler|
 // with results of the evaluation (which may be nil if the implementing object
 // has no way to run the evaluation or the evaluation returns a nil value)
 // or an NSError if there is an error. The |completionHandler| can be nil.
+// TODO(crbug.com/595761): Change this API to return |id| instead of string.
 - (void)evaluateJavaScript:(NSString*)script
        stringResultHandler:(web::JavaScriptCompletion)handler;
 
 // Checks to see if the script for a class has been injected into the
 // current page already, given the class and the script's presence
 // beacon (a JS object that should exist iff the script has been injected).
 - (BOOL)scriptHasBeenInjectedForClass:(Class)jsInjectionManagerClass
                        presenceBeacon:(NSString*)beacon;
 
 // Injects the given script into the current page on behalf of
 // |jsInjectionManagerClass|. This should only be used for injecting
 // the manager's script, and not for evaluating arbitrary JavaScript.
 - (void)injectScript:(NSString*)script forClass:(Class)jsInjectionManagerClass;
 
 // Returns type of web view used for evaluation. Must not change for the
 // lifetime of the object.
 - (web::WebViewType)webViewType;
 
 @end
 
 #endif  // IOS_WEB_PUBLIC_WEB_STATE_JS_CRW_JS_INJECTION_EVALUATOR_H_