--- a/gfx/layers/Layers.cpp
+++ b/gfx/layers/Layers.cpp
@@ -1050,17 +1050,17 @@ Layer::GetVisibleRegionRelativeToRootLay
     // remove these areas from the visible region as well. This will pick up
     // chrome overlays like a tab modal prompt.
     Layer* sibling;
     for (sibling = layer->GetNextSibling(); sibling;
          sibling = sibling->GetNextSibling()) {
       gfx::Matrix siblingMatrix;
       if (!sibling->GetLocalTransform().Is2D(&siblingMatrix) ||
           !siblingMatrix.IsTranslation()) {
-        return false;
+        continue;
       }
 
       // Retreive the translation from sibling to |layer|. The accumulated
       // visible region is currently oriented with |layer|.
       IntPoint siblingOffset = RoundedToInt(siblingMatrix.GetTranslation());
       nsIntRegion siblingVisibleRegion(sibling->GetLocalVisibleRegion().ToUnknownRegion());
       // Translate the siblings region to |layer|'s origin.
       siblingVisibleRegion.MoveBy(-siblingOffset.x, -siblingOffset.y);