Add HttpProtocolHandler and convert everything to use it

net/url_request/http_protocol_handler.cc

+// Copyright 2016 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.
+
+#include "net/url_request/http_protocol_handler.h"
+#include "net/url_request/url_request.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_error_job.h"
+#include "net/url_request/url_request_http_job.h"
+#include "net/url_request/url_request_redirect_job.h"
+#include "url/gurl.h"
+
+namespace net {
+
+HttpProtocolHandler::HttpProtocolHandler() {}
+
+URLRequestJob* HttpProtocolHandler::MaybeCreateJob(
+    URLRequest* request,
+    NetworkDelegate* network_delegate) const {
+  DCHECK(request->url().scheme() == "http" ||
+         request->url().scheme() == "https" ||
+         request->url().scheme() == "ws" || request->url().scheme() == "wss");

[mmenke, 2016/04/28 16:52:41]

nit:  While you're here, mind switching these to the corresponding
url_constants?

[mgersh, 2016/04/28 20:36:30]

Done.

+
+  if (!request->context()->http_transaction_factory()) {
+    NOTREACHED() << "requires a valid context";

[mmenke, 2016/04/28 16:52:41]

nit:  include base/logging for NOTREACHED

[mgersh, 2016/04/28 20:36:30]

Done.

+    return new URLRequestErrorJob(request, network_delegate,
+                                  ERR_INVALID_ARGUMENT);

[mmenke, 2016/04/28 16:52:41]

nit:  Include net/base/net_error.h

[mgersh, 2016/04/28 20:36:30]

Done.

+  }
+
+  GURL redirect_url;
+  if (request->GetHSTSRedirect(&redirect_url)) {
+    return new URLRequestRedirectJob(
+        request, network_delegate, redirect_url,
+        // Use status code 307 to preserve the method, so POST requests work.
+        URLRequestRedirectJob::REDIRECT_307_TEMPORARY_REDIRECT, "HSTS");
+  }
+  return new URLRequestHttpJob(request, network_delegate,
+                               request->context()->http_user_agent_settings());
+}
+
+}  // namespace net