layout: Implement flow tree dumping with RUST_LOG=debug is on.

r? @pcwalton

1 files changed, 4 insertions, 1 deletions

diff --git a/components/layout/layout_task.rs b/components/layout/layout_task.rs
index db47f9e5801..749510c56d5 100644
--- a/components/layout/layout_task.rs
+++ b/components/layout/layout_task.rs
@@ -30,6 +30,7 @@ use gfx::render_task::{RenderInitMsg, RenderChan, RenderLayer};
 use gfx::{render_task, color};
 use layout_traits;
 use layout_traits::{LayoutControlMsg, LayoutTaskFactory};
+use log;
 use script::dom::bindings::js::JS;
 use script::dom::node::{ElementNodeTypeId, LayoutDataRef, Node};
 use script::dom::element::{HTMLBodyElementTypeId, HTMLHtmlElementTypeId};
@@ -566,7 +567,9 @@ impl LayoutTask {
 
         debug!("layout: received layout request for: {:s}", data.url.serialize());
         debug!("layout: parsed Node tree");
-        debug!("{:?}", node.dump());
+        if log_enabled!(log::DEBUG) {
+            node.dump();
+        }
 
         let mut rw_data = self.lock_rw_data(possibly_locked_rw_data);