Split up ios/web:test_support.

ios/web/public/test/response_providers/http_auth_response_provider.mm

-// Copyright 2017 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/web/public/test/response_providers/http_auth_response_provider.h"
-
-#include "base/base64.h"
-#include "base/strings/stringprintf.h"
-#include "net/http/http_request_headers.h"
-#include "net/http/http_response_headers.h"
-
-namespace web {
-
-HttpAuthResponseProvider::HttpAuthResponseProvider(const GURL& url,
-                                                   const std::string& realm,
-                                                   const std::string& username,
-                                                   const std::string& password)
-    : url_(url), realm_(realm), username_(username), password_(password) {}
-
-HttpAuthResponseProvider::~HttpAuthResponseProvider() = default;
-
-bool HttpAuthResponseProvider::CanHandleRequest(const Request& request) {
-  return request.url == url_;
-}
-
-void HttpAuthResponseProvider::GetResponseHeadersAndBody(
-    const Request& request,
-    scoped_refptr<net::HttpResponseHeaders>* headers,
-    std::string* response_body) {
-  if (HeadersHaveValidCredentials(request.headers)) {
-    *response_body = page_text();
-    *headers = GetDefaultResponseHeaders();
-  } else {
-    *headers = GetResponseHeaders("", net::HTTP_UNAUTHORIZED);
-    (*headers)->AddHeader(base::StringPrintf(
-        "WWW-Authenticate: Basic realm=\"%s\"", realm_.c_str()));
-  }
-}
-
-bool HttpAuthResponseProvider::HeadersHaveValidCredentials(
-    const net::HttpRequestHeaders& headers) {
-  std::string header;
-  if (headers.GetHeader(net::HttpRequestHeaders::kAuthorization, &header)) {
-    std::string auth =
-        base::StringPrintf("%s:%s", username_.c_str(), password_.c_str());
-    std::string encoded_auth;
-    base::Base64Encode(auth, &encoded_auth);
-    return header == base::StringPrintf("Basic %s", encoded_auth.c_str());
-  }
-  return false;
-}
-
-}  // namespace web