Delete "Experimental WebSocket" flag from chrome://flags.

content/renderer/web_preferences.cc

 // Copyright 2013 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.
 
 #include "content/public/renderer/web_preferences.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebKit.h"
@@ skipping 332 matching lines @@
       prefs.clobber_user_agent_initial_scale_quirk);
   settings->setIgnoreMainFrameOverflowHiddenQuirk(
       prefs.ignore_main_frame_overflow_hidden_quirk);
   settings->setReportScreenSizeInPhysicalPixelsQuirk(
       prefs.report_screen_size_in_physical_pixels_quirk);
   settings->setMainFrameClipsContent(false);
   settings->setShrinksStandaloneImagesToFit(false);
 #endif
 
   WebNetworkStateNotifier::setOnLine(prefs.is_online);
-  settings->setExperimentalWebSocketEnabled(
-      prefs.experimental_websocket_enabled);
   settings->setPinchVirtualViewportEnabled(
       prefs.pinch_virtual_viewport_enabled);
 
   settings->setPinchOverlayScrollbarThickness(
       prefs.pinch_overlay_scrollbar_thickness);
   settings->setUseSolidColorScrollbars(prefs.use_solid_color_scrollbars);
   settings->setCompositorTouchHitTesting(prefs.compositor_touch_hit_testing);
 }
 
 }  // namespace content