[ios] Remove CWV_IMPLEMENTATION hack in ChromeWebView implementation.

ios/web_view/public/ChromeWebView.h

Index: ios/web_view/public/ChromeWebView.h
diff --git a/ios/web_view/public/ChromeWebView.h b/ios/web_view/public/ChromeWebView.h
new file mode 100644
index 0000000000000000000000000000000000000000..164807de31123b45930e773ad100c306905b5ff9
--- /dev/null
+++ b/ios/web_view/public/ChromeWebView.h
@@ -0,0 +1,23 @@
+// 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_CHROMEWEBVIEW_H_
+#define IOS_WEB_VIEW_PUBLIC_CHROMEWEBVIEW_H_
+
+#import "cwv_export.h"
+
+#import "cwv.h"
+#import "cwv_delegate.h"
+#import "cwv_html_element.h"
+#import "cwv_navigation_action.h"
+#import "cwv_navigation_delegate.h"
+#import "cwv_translate_delegate.h"
+#import "cwv_translate_manager.h"
+#import "cwv_ui_delegate.h"
+#import "cwv_user_content_controller.h"
+#import "cwv_user_script.h"
+#import "cwv_web_view.h"
+#import "cwv_web_view_configuration.h"
+
+#endif  // IOS_WEB_VIEW_PUBLIC_CHROMEWEBVIEW_H_