[ios] Removed UIWebView JS evaluation code.

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

Index: ios/web/public/web_state/js/crw_js_injection_evaluator.h
diff --git a/ios/web/public/web_state/js/crw_js_injection_evaluator.h b/ios/web/public/web_state/js/crw_js_injection_evaluator.h
index 3264b03fcd98afc4f0e8d9a5b6413bcc47be6ffa..b0445997210baabc9a476a04d9dea955dd464d98 100644
--- a/ios/web/public/web_state/js/crw_js_injection_evaluator.h
+++ b/ios/web/public/web_state/js/crw_js_injection_evaluator.h
@@ -21,6 +21,7 @@ typedef void (^JavaScriptCompletion)(NSString*, NSError*);
 // 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;