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 0705997be032a61123ca189fcca3b16721a5aca3..e9445dfe98dd6f52a98d331710af478f211b1230 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2120,6 +2120,11 @@ const FeatureEntry kFeatureEntries[] = {
      IDS_FLAGS_AUTOMATIC_TAB_DISCARDING_DESCRIPTION, kOsWin | kOsMac,
      FEATURE_VALUE_TYPE(features::kAutomaticTabDiscarding)},
 #endif  // OS_WIN || OS_MACOSX
+    {"enable-pointer-events",  // FLAGS:RECORD_UMA
+      IDS_FLAGS_EXPERIMENTAL_POINTER_EVENT_NAME,
+      IDS_FLAGS_EXPERIMENTAL_POINTER_EVENT_DESCRIPTION,
+      kOsAll,
+      SINGLE_VALUE_TYPE(switches::kEnablePointerEvents)},
     // 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.