Re-land r41544 "Update dart binaries used for running tests to version 1.7.2"

tools/testing/dart/http_server.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library http_server;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'dart:convert' show
@@ skipping 38 matching lines @@
 
 /// Interface of the HTTP server:
 ///
 /// /echo: This will stream the data received in the request stream back
 ///        to the client.
 /// /root_dart/X: This will serve the corresponding file from the dart
 ///               directory (i.e. '$DartDirectory/X').
 /// /root_build/X: This will serve the corresponding file from the build
 ///                directory (i.e. '$BuildDirectory/X').
 /// /FOO/packages/BAR: This will serve the corresponding file from the packages
-///                    directory (i.e. '$BuildDirectory/packages/BAR') or the 
+///                    directory (i.e. '$BuildDirectory/packages/BAR') or the
 ///                    passed-in package root
 /// /ws: This will upgrade the connection to a WebSocket connection and echo
 ///      all data back to the client.
 ///
 /// In case a path does not refer to a file but rather to a directory, a
 /// directory listing will be displayed.
 
 const PREFIX_BUILDDIR = 'root_build';
 const PREFIX_DARTDIR = 'root_dart';
 
@@ skipping 67 matching lines @@
   final String runtime;
   DispatchingServer _server;
 
   TestingServers(Path buildDirectory,
                  this.useContentSecurityPolicy,
                  [String this.runtime = 'none', String dartDirectory,
                   String packageRoot]) {
     _buildDirectory = TestUtils.absolutePath(buildDirectory);
     _dartDirectory = dartDirectory == null ? TestUtils.dartDir
         : new Path(dartDirectory);
-    _packageRoot = packageRoot == null ? 
+    _packageRoot = packageRoot == null ?
       _buildDirectory.append('packages') :
       new Path(packageRoot);
   }
 
   int get port => _serverList[0].port;
   int get crossOriginPort => _serverList[1].port;
   DispatchingServer get server => _server;
 
   /**
    * [startServers] will start two Http servers.
@@ skipping 234 matching lines @@
       if (const ["safari"].contains(runtime)) {
         response.headers.set("X-WebKit-CSP", content_header_value);
       }
     }
     if (path.filename.endsWith('.html')) {
       response.headers.set('Content-Type', 'text/html');
     } else if (path.filename.endsWith('.js')) {
       response.headers.set('Content-Type', 'application/javascript');
     } else if (path.filename.endsWith('.dart')) {
       response.headers.set('Content-Type', 'application/dart');
+    } else if (path.filename.endsWith('.css')) {
+      response.headers.set('Content-Type', 'text/css');
     }
     response.headers.removeAll("X-Frame-Options");
     file.openRead().pipe(response).catchError((e) {
       DebugLogger.warning(
           'HttpServer: error while closing the response stream', e);
     });
   }
 
   void _sendNotFound(HttpRequest request) {
     bool isHarmlessPath(String path) {
@@ skipping 39 matching lines @@
 class _Entry implements Comparable {
   final String name;
   final String displayName;
 
   _Entry(this.name, this.displayName);
 
   int compareTo(_Entry other) {
     return name.compareTo(other.name);
   }
 }