Added integration test to Chrome Proxy to verify direct connection on remote site timeout

tools/chrome_proxy/testserver/server.go

 // 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.
 //
 // Test server to facilitate the data reduction proxy Telemetry tests.
 //
 // The server runs at http://chromeproxy-test.appspot.com/. Please contact
 // people in OWNERS for server issues.
 //
 // For running an AppEngine Go server, see:
@@ skipping 17 matching lines @@
 import (
         "bytes"
         "encoding/base64"
         "encoding/json"
         "errors"
         "fmt"
         "io"
         "net/http"
         "os"
         "strconv"
+        "strings"
+        "time"
 )
 
 func init() {
         http.HandleFunc("/requestHeader", requestHeader)
         http.HandleFunc("/resource", resource)
         http.HandleFunc("/default", defaultResponse)
+        http.HandleFunc("/blackhole", blackholeProxy)
 }
 
 // requestHander returns request headers in response body as text.
 func requestHeader(w http.ResponseWriter, r *http.Request) {
         r.Header.Write(w)
 }
 
 // resource returns the content of a data file specified by "r=" query as the response body.
 // The response could be overridden by request queries.
 // See parseOverrideQuery.
@@ skipping 21 matching lines @@
 func defaultResponse(w http.ResponseWriter, r *http.Request) {
         wroteBody, err := applyOverride(w, r)
         if err != nil {
                 return
         }
         if !wroteBody {
                 w.Write([]byte("ok"))
         }
 }
 
+// blackholePoxy delays 90 seconds for proxied responses, in order to test if
+// the proxy will timeout on the site. Responds immediately to any other request.
+func blackholeProxy(w http.ResponseWriter, r *http.Request) {
+        if strings.Contains(r.Header.Get("via"), "Chrome-Compression-Proxy") {
+                // Causes timeout on proxy, will then send BLOCK_ONCE.
+                // Appspot will 502 traffic at 120 seconds with no response.
+                time.Sleep(90 * time.Second);
+                w.Write([]byte("You are proxy"));
+        } else {
+                w.Write([]byte("You are direct"));
+        }
+}
+
 type override struct {
         status int
         header http.Header
         body   io.Reader
 }
 
 // parseOverrideQuery parses the queries in r and returns an override.
 // It supports the following queries:
 //   "respStatus": an integer to override response status code;
 //   "respHeader": base64 encoded JSON data to override the response headers;
@@ skipping 59 matching lines @@
         return false, nil
 }
 
 func writeFromFile(w io.Writer, filename string) (int64, error) {
         f, err := os.Open(filename)
         if err != nil {
                 return 0, err
         }
         return io.Copy(w, f)
 }