2 files changed, 8 insertions, 6 deletions
diff --git a/components/compositing/compositor.rs b/components/compositing/compositor.rs
index f618077f5ea..346666ac31b 100644
--- a/components/compositing/compositor.rs
+++ b/components/compositing/compositor.rs
@@ -1288,8 +1288,13 @@ impl<Window: WindowMethods> IOCompositor<Window> {
         self.composite_specific_target(target);
     }
 
-    fn composite_specific_target(&mut self, target: CompositeTarget) -> Option<png::Image> {
-        if !self.window.prepare_for_composite() {
+    pub fn composite_specific_target(&mut self, target: CompositeTarget) -> Option<png::Image> {
+        if !self.context.is_some() {
+            return None
+        }
+        let (width, height) =
+            (self.window_size.width.get() as usize, self.window_size.height.get() as usize);
+        if !self.window.prepare_for_composite(width, height) {
             return None
         }
 
@@ -1302,9 +1307,6 @@ impl<Window: WindowMethods> IOCompositor<Window> {
             _ => {}
         }
 
-        let (width, height) =
-            (self.window_size.width.get() as usize, self.window_size.height.get() as usize);
-
         let (framebuffer_ids, texture_ids) = match target {
             CompositeTarget::Window => (vec!(), vec!()),
             _ => initialize_png(width, height)
diff --git a/components/compositing/windowing.rs b/components/compositing/windowing.rs
index 51b13bfdf81..196e1e2653f 100644
--- a/components/compositing/windowing.rs
+++ b/components/compositing/windowing.rs
@@ -123,7 +123,7 @@ pub trait WindowMethods {
     /// Requests that the window system prepare a composite. Typically this will involve making
     /// some type of platform-specific graphics context current. Returns true if the composite may
     /// proceed and false if it should not.
-    fn prepare_for_composite(&self) -> bool;
+    fn prepare_for_composite(&self, width: usize, height: usize) -> bool;
 
     /// Sets the cursor to be used in the window.
     fn set_cursor(&self, cursor: Cursor);