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

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index 906280cd92964fa5189864b5416c41fa9cd9ab27..41b3e40029b793a7cff15b0d278f7dde6770b196 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -210,6 +210,11 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   if (base::FeatureList::IsEnabled(features::kWebFontsIntervention))
     WebRuntimeFeatures::enableWebFontsIntervention(true);
 
+  if (base::FeatureList::IsEnabled(features::kPointerEvents)) {
+      WebRuntimeFeatures::enableFeatureFromString(
+        std::string("PointerEvent"), true);
+  }
+
   // Enable explicitly enabled features, and then disable explicitly disabled
   // ones.
   if (command_line.HasSwitch(switches::kEnableBlinkFeatures)) {