move chrome_proxy test server to tools/chrome_proxy.

tools/chrome_proxy/testserver/server.go

 // 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:
 // https://developers.google.com/appengine/docs/go/gettingstarted/introduction.
 //
 // The goal is to keep the test logic on the client side (Telemetry)
 // as much as possible. This server will only return a resource
@@ skipping 139 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)
 }