Add enable flag for pointer events in about://flags

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index d292251a71ff3f59da3597581d7f3871c8198cf0..13471af932448ea904d0bfdc2147c1fa99835917 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1819,6 +1819,11 @@ const FeatureEntry kFeatureEntries[] = {
      IDS_FLAGS_MEDIA_STYLE_NOTIFICATION_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(chrome::android::kMediaStyleNotification)},
 #endif
+    {"enable-pointer-events",  // FLAGS:RECORD_UMA
+      IDS_FLAGS_EXPERIMENTAL_POINTER_EVENT_NAME,
+      IDS_FLAGS_EXPERIMENTAL_POINTER_EVENT_DESCRIPTION,
+      kOsAll,
+      FEATURE_VALUE_TYPE(features::kPointerEvents)},
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.