[ios] Remove CWV_IMPLEMENTATION hack in ChromeWebView implementation.

ios/web_view/public/cwv_navigation_delegate.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 IOS_WEB_VIEW_PUBLIC_CWV_NAVIGATION_DELEGATE_H_
 #define IOS_WEB_VIEW_PUBLIC_CWV_NAVIGATION_DELEGATE_H_
 
 #import <Foundation/Foundation.h>
 
-// TODO(crbug.com/704946): Make framework style include work everywhere and
-// remove this #if.
-#if defined(CWV_IMPLEMENTATION)
-#include "ios/web_view/public/cwv_export.h"
-#else
-#include <ChromeWebView/cwv_export.h>
-#endif
+#import "cwv_export.h"
 
 @protocol CRIWVTranslateDelegate;
 @class CWVWebView;
 
 // Navigation delegate protocol for CWVWebViews.  Allows embedders to hook
 // page loading and receive events for navigation.
 CWV_EXPORT
 @protocol CWVNavigationDelegate<NSObject>
 @optional
 
@@ skipping 18 matching lines @@
 // both success and failure cases.
 - (void)webView:(CWVWebView*)webView didLoadPageWithSuccess:(BOOL)success;
 
 // Notifies the delegate that web view process was terminated
 // (usually by crashing, though possibly by other means).
 - (void)webViewWebContentProcessDidTerminate:(CWVWebView*)webView;
 
 @end
 
 #endif  // IOS_WEB_VIEW_PUBLIC_CWV_NAVIGATION_DELEGATE_H_