Mac: Prevent NTP mousewheel events from being suppressed on Lion.

base/mac/mac_util.mm

Index: base/mac/mac_util.mm
diff --git a/base/mac/mac_util.mm b/base/mac/mac_util.mm
index ad735968f35d50c9d8fab0c9d059f4e7af1fa115..6c45d51f4882bdf36e555a6a19b895cb029280ae 100644
--- a/base/mac/mac_util.mm
+++ b/base/mac/mac_util.mm
@@ -696,5 +696,11 @@ bool ParseModelIdentifier(const std::string& ident,
   return true;
 }
 
+bool IsSwipeTrackingFromScrollEventsEnabled() {
+  SEL selector = @selector(isSwipeTrackingFromScrollEventsEnabled);
+  return [NSEvent respondsToSelector:selector]
+      && [NSEvent performSelector:selector];
+}
+
 }  // namespace mac
 }  // namespace base