IWYU fixes for url/...

url/url_canon_icu.h

 // Copyright 2013 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 URL_URL_CANON_ICU_H_
 #define URL_URL_CANON_ICU_H_
 
 // ICU integration functions.
 
 #include "base/compiler_specific.h"
+#include "base/strings/string16.h"
+#include "unicode/ucnv_err.h"
 #include "url/url_canon.h"
 #include "url/url_export.h"
 
 typedef struct UConverter UConverter;
 
 namespace url {
 
 // An implementation of CharsetConverter that implementations can use to
 // interface the canonicalizer with ICU's conversion routines.
 class URL_EXPORT ICUCharsetConverter : public CharsetConverter {
@@ skipping 10 matching lines @@
                         CanonOutput* output) override;
 
  private:
   // The ICU converter, not owned by this class.
   UConverter* converter_;
 };
 
 }  // namespace url
 
 #endif  // URL_URL_CANON_ICU_H_