Mac: Remove flag to disable threaded event handling

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index a5a391778004a7dca52aff0136813f8a3e7ce9e1..d32ea245129cd0f3f5b33c7a20e76ca4cc8764a1 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -553,10 +553,7 @@ void RenderThreadImpl::Init() {
   is_one_copy_enabled_ = !command_line.HasSwitch(switches::kDisableOneCopy);
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
-  is_elastic_overscroll_enabled_ =
-      !base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kDisableThreadedEventHandlingMac) &&
-      base::mac::IsOSLionOrLater();
+  is_elastic_overscroll_enabled_ = base::mac::IsOSLionOrLater();
   if (is_elastic_overscroll_enabled_) {
     base::ScopedCFTypeRef<CFStringRef> key(
         base::SysUTF8ToCFStringRef("NSScrollViewRubberbanding"));