Fix Observatory by disabling WebSocket compression

runtime/bin/vmservice/server.dart

Index: runtime/bin/vmservice/server.dart
diff --git a/runtime/bin/vmservice/server.dart b/runtime/bin/vmservice/server.dart
index 394315f4527c3e6f9bc4b735ba70757f09371bf0..69e9b2e6b68c7501fecefc9f5cae10733f6a8ad0 100644
--- a/runtime/bin/vmservice/server.dart
+++ b/runtime/bin/vmservice/server.dart
@@ -130,7 +130,9 @@ 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;