mac: Delete more 10.5-only code

webkit/plugins/npapi/webplugin_delegate_impl_mac.mm

Index: webkit/plugins/npapi/webplugin_delegate_impl_mac.mm
diff --git a/webkit/plugins/npapi/webplugin_delegate_impl_mac.mm b/webkit/plugins/npapi/webplugin_delegate_impl_mac.mm
index 35d3f719a7247612c8b6126c767788a00bce66d5..797d96be5504f5bbc8549af7ba4e6d5fcf13a5d7 100644
--- a/webkit/plugins/npapi/webplugin_delegate_impl_mac.mm
+++ b/webkit/plugins/npapi/webplugin_delegate_impl_mac.mm
@@ -959,11 +959,8 @@ void WebPluginDelegateImpl::PluginVisibilityChanged() {
 }
 
 void WebPluginDelegateImpl::StartIme() {
-  // Currently the plugin IME implementation only works on 10.6.
-  if (instance()->event_model() != NPEventModelCocoa ||
-      base::mac::IsOSLeopardOrEarlier()) {
+  if (instance()->event_model() != NPEventModelCocoa)
     return;
-  }
   if (ime_enabled_)
     return;
   ime_enabled_ = true;