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

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index d904a83099ec4cb8acab4a74f3ffd29df0665bd0..e999affe568f1ce20192488afe9d61a284738aac 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -58,6 +58,10 @@ const base::Feature kOptimizeIPCForSmallResource{
     "OptimizeForSmallResource",
     base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Partial support for pointer event feature.
+const base::Feature kPointerEvents{"PointerEvent",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Throttle Blink's rendering pipeline based on frame visibility.
 const base::Feature kRenderingPipelineThrottling{
     "RenderingPipelineThrottling", base::FEATURE_DISABLED_BY_DEFAULT};