Remove use of void** from HttpResponseHeaders::EnumerateHeaderLines

mojo/services/network/url_loader_impl.cc

Index: mojo/services/network/url_loader_impl.cc
diff --git a/mojo/services/network/url_loader_impl.cc b/mojo/services/network/url_loader_impl.cc
index bcd73f1fc0b80445e644e8b8cfbd8ac7975ee35f..99e359d79603fc80b7b8dc43ba1972d371f6b4a9 100644
--- a/mojo/services/network/url_loader_impl.cc
+++ b/mojo/services/network/url_loader_impl.cc
@@ -77,7 +77,7 @@ URLResponsePtr MakeURLResponse(const net::URLRequest* url_request) {
 
     response->headers = Array<HttpHeaderPtr>::New(0);
     std::vector<String> header_lines;
-    void* iter = nullptr;
+    size_t iter = 0;
     std::string name, value;
     while (headers->EnumerateHeaderLines(&iter, &name, &value)) {
       HttpHeaderPtr header = HttpHeader::New();