Update service isolate server script

sky/engine/core/script/dart_service_isolate/server.dart

@@ -90,21 +90,6 @@ class Server {
     _displayMessages = (_ip != '127.0.0.1' || _port != 8181);
   }
 
-  bool _shouldServeObservatory(HttpRequest request) {
-    if (request.headers['Observatory-Version'] != null) {
-      // Request is already coming from Observatory.
-      return false;
-    }
-    // TODO(johnmccutchan): Test with obscure browsers.
-    if (request.headers.value(HttpHeaders.USER_AGENT).contains('Mozilla')) {
-      // Request is coming from a browser but not Observatory application.
-      // Serve Observatory and let the Observatory make the real request.
-      return true;
-    }
-    // All other user agents are assumed to be textual.
-    return false;
-  }
-
   _onServerShutdown() {
   }
 
@@ -132,17 +117,15 @@ class Server {
           request.uri.path == '/' ? ROOT_REDIRECT_PATH : request.uri.path;
 
     if (path == WEBSOCKET_PATH) {
-      WebSocketTransformer.upgrade(request).then((WebSocket webSocket) {
+      WebSocketTransformer.upgrade(request,
+                                   compression: CompressionOptions.OFF).then(
+                                   (WebSocket webSocket) {
         new WebSocketClient(webSocket, _service);
       });
       return;
     }
 
     Asset asset = assets[path];
-    if (asset == null && _shouldServeObservatory(request)) {
-      asset = assets[ROOT_REDIRECT_PATH];
-      assert(asset != null);
-    }
     if (asset != null) {
       // Serving up a static resource (e.g. .css, .html, .png).
       request.response.headers.contentType =