Make scrollAnimatorEnabled work on Mac like it does on other platforms

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 75d53c90961086c6225b352981d181a8d5733524..03e6678095ced3683e5e2540d3bdbcaa47336ef5 100644
--- a/base/mac/mac_util.mm
+++ b/base/mac/mac_util.mm
@@ -603,5 +603,21 @@ bool ParseModelIdentifier(const std::string& ident,
   return true;
 }
 
+bool IsScrollAnimationEnabled() {
+  bool enabled = false;
+  id value = nil;
+  if (base::mac::IsOSMountainLionOrLater()) {
+    value = [[NSUserDefaults standardUserDefaults]
+        objectForKey:@"NSScrollAnimationEnabled"];
+  } else {
+    value = [[NSUserDefaults standardUserDefaults]
+        objectForKey:@"AppleScrollAnimationEnabled"];
+  }
+  if (value)
+    enabled = [value boolValue];
+  return enabled;
+}
+
+
 }  // namespace mac
 }  // namespace base