Remove use of void** from HttpResponseHeaders::EnumerateHeaderLines

ios/net/protocol_handler_util.mm

 // 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.
 
 #import "ios/net/protocol_handler_util.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/i18n/icu_encoding_detection.h"
@@ skipping 72 matching lines @@
     return [[[NSURLResponse alloc] initWithURL:url
                                       MIMEType:mime_type
                          expectedContentLength:-1
                               textEncodingName:charset] autorelease];
   } else {
     // Iterate over all the headers and copy them.
     bool has_content_type_header = false;
     NSMutableDictionary* header_fields = [NSMutableDictionary dictionary];
     HttpResponseHeaders* headers = request->response_headers();
     if (headers != nullptr) {
-      void* iter = nullptr;
+      size_t iter = 0;
       std::string name, value;
       while (headers->EnumerateHeaderLines(&iter, &name, &value)) {
         NSString* key = base::SysUTF8ToNSString(name);
         if (!key) {
           DLOG(ERROR) << "Header name is not in UTF8: " << name;
           // Skip the invalid header.
           continue;
         }
         // Do not copy "Cache-Control" headers as we provide our own controls.
         if ([key caseInsensitiveCompare:@"cache-control"] == NSOrderedSame)
@@ skipping 100 matching lines @@
   if (out_request->has_upload() && out_request->method() == "POST") {
     DLOG_IF(WARNING, !net_headers.HasHeader(HttpRequestHeaders::kContentType))
         << "Missing \"Content-Type\" header in POST request.";
     net_headers.SetHeaderIfMissing(HttpRequestHeaders::kContentType,
                                    "application/x-www-form-urlencoded");
   }
   out_request->SetExtraRequestHeaders(net_headers);
 }
 
 }  // namespace net