Added experiment for changing viewport scroll ordering.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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 "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 1835 matching lines @@
   },
 #endif
   {
     "disable-threaded-scrolling",
     IDS_FLAGS_DISABLE_THREADED_SCROLLING_NAME,
     IDS_FLAGS_DISABLE_THREADED_SCROLLING_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS | kOsAndroid | kOsMac,
     SINGLE_VALUE_TYPE(switches::kDisableThreadedScrolling)
   },
   {
+    "enable-viewport-scroll-order-experiment",
+    IDS_FLAGS_ENABLE_VIEWPORT_SCROLL_ORDER_EXPERIMENT_NAME,
+    IDS_FLAGS_ENABLE_VIEWPORT_SCROLL_ORDER_EXPERIMENT_DESCRIPTION,
+    kOsAll,
+    SINGLE_VALUE_TYPE(switches::kEnableViewportScrollOrderExperiment)
+  },
+  {
     "bleeding-edge-renderer-mode",
     IDS_FLAGS_BLEEDING_RENDERER_NAME,
     IDS_FLAGS_BLEEDING_RENDERER_DESCRIPTION,
     kOsAndroid,
     SINGLE_VALUE_TYPE(switches::kEnableBleedingEdgeRenderingFastPaths)
   },
   {
     "enable-settings-window",
     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_NAME,
     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_DESCRIPTION,
@@ skipping 1131 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags