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

base/mac/mac_util.h

Index: base/mac/mac_util.h
diff --git a/base/mac/mac_util.h b/base/mac/mac_util.h
index a308ccd8635f74548e3e4335f5027a3a0e297e9c..42a9904c57492d8ac3d8516c5e45745f6d8a6026 100644
--- a/base/mac/mac_util.h
+++ b/base/mac/mac_util.h
@@ -207,6 +207,11 @@ BASE_EXPORT bool ParseModelIdentifier(const std::string& ident,
                                       int32* major,
                                       int32* minor);
 
+// On 10.7+, back and forward swipe gestures can be triggered using a scroll
+// gesture, if enabled in System Preferences. This function returns true if
+// the feature is supported and enabled, and false otherwise.
+BASE_EXPORT bool IsSwipeTrackingFromScrollEventsEnabled();
+
 }  // namespace mac
 }  // namespace base