Introduce Http{Request,Response} mojom structs.

mojo/services/network/public/interfaces/url_loader.mojom

 // Copyright 2014 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.
 
 module mojo;
 
+import "network/public/interfaces/http_message.mojom";
 import "network/public/interfaces/network_error.mojom";
 
-struct HTTPHeader {
-  string name;
-  string value;
-};
-
 struct URLRequest {
   // The URL to load.
   string url;
 
   // The HTTP method if applicable.
   string method = "GET";
 
   // Additional HTTP request headers.
-  array<HTTPHeader>? headers;
+  array<HttpHeader>? headers;
 
   // The payload for the request body, represented as a concatenation of data
   // streams. For HTTP requests, the method must be set to "POST" or "PUT".
   array<handle<data_pipe_consumer>>? body;
 
   // The buffer size of the data pipe returned in URLResponse's |body| member.
   // A value of 0 indicates that the default buffer size should be used.  This
   // value is just a suggestion. The URLLoader may choose to ignore this value.
   uint32 response_body_buffer_size = 0;
 
@@ skipping 19 matching lines @@
   // The final URL of the response, after redirects have been followed.
   string? url;
 
   // The HTTP status code. 0 if not applicable.
   uint32 status_code;
 
   // The HTTP status line.
   string? status_line;
 
   // The HTTP response headers.
-  array<HTTPHeader>? headers;
+  array<HttpHeader>? headers;
 
   // The MIME type of the response body.
   string? mime_type;
 
   // The character set of the response body.
   string? charset;
 
   // These fields are set to non-NULL if this response corresponds to a
   // redirect.  Call the |FollowRedirect| method on the URLLoader instance to
   // follow this redirect.
@@ skipping 23 matching lines @@
   Start(URLRequest request) => (URLResponse response);
 
   // If the request passed to |Start| had |auto_follow_redirects| set to false,
   // then upon receiving an URLResponse with a non-NULL |redirect_url| field,
   // |FollowRedirect| may be called to load the URL indicated by the redirect.
   FollowRedirect() => (URLResponse response);
 
   // Query status about the URLLoader.
   QueryStatus() => (URLLoaderStatus status);
 };