Force events to be non blocking if main thread is unresponsive.

content/public/common/content_features.cc

 // Copyright 2015 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 "build/build_config.h"
 #include "content/public/common/content_features.h"
 
 namespace features {
 
 // All features in alphabetical order.
@@ skipping 49 matching lines @@
 const base::Feature kMediaDocumentDownloadButton{
     "MediaDocumentDownloadButton",
     base::FEATURE_DISABLED_BY_DEFAULT
 };
 
 // Enable the material design playback UI for media elements.  This is always
 // on for OS_ANDROID, but may be enabled by experiment for other platforms.
 const base::Feature kNewMediaPlaybackUi{"NewMediaPlaybackUi",
                                         base::FEATURE_ENABLED_BY_DEFAULT};
 
+// An experiment forcing events to be non-blocking when the main thread is
+// deemed unresponsive.  See crbug.com/599609.
+const base::Feature kMainThreadBusyScrollIntervention{
+    "MainThreadBusyScrollIntervention", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Non-validating reload for desktop.
 // See https://crbug.com/591245
 const base::Feature kNonValidatingReloadOnNormalReload{
     "NonValidatingReloadOnNormalReload", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Non-validating reload on reload-to-refresh-content (e.g. pull-to-refresh).
 // See https://crbug.com/591245
 const base::Feature kNonValidatingReloadOnRefreshContent{
     "NonValidatingReloadOnRefreshContentV2",
     base::FEATURE_DISABLED_BY_DEFAULT};
@@ skipping 14 matching lines @@
 
 // Whether the lookahead parser in Blink runs on the main thread.
 const base::Feature kParseHTMLOnMainThread{"ParseHTMLOnMainThread",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Whether document level event listeners should default 'passive' to true.
 const base::Feature kPassiveDocumentEventListeners{
     "PassiveDocumentEventListeners", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Whether we should force a touchstart and first touchmove per scroll event
-// listeners to be 'passive' during fling.
+// listeners to be non-blocking during fling.
 const base::Feature kPassiveEventListenersDueToFling{
     "PassiveEventListenersDueToFling", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Pointer events support.
 const base::Feature kPointerEvents{"PointerEvent",
                                    base::FEATURE_DISABLED_BY_DEFAULT};
 
 // If Pepper 3D Image Chromium is allowed, this feature controls whether it is
 // enabled.
 const base::Feature kPepper3DImageChromium{"Pepper3DImageChromium",
@@ skipping 70 matching lines @@
 #endif
 
 #if defined(OS_WIN)
 // Emergency "off switch" for new Windows sandbox security mitigation,
 // sandbox::MITIGATION_EXTENSION_POINT_DISABLE.
 const base::Feature kWinSboxDisableExtensionPoints{
     "WinSboxDisableExtensionPoint", base::FEATURE_ENABLED_BY_DEFAULT};
 #endif
 
 }  // namespace features