Stop displaying layers with non-invertible transforms.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 4a945a224384de89251c3b1d7a2b888f932c4999..f3ce4720f2b6656aa15bd0fefbdd16a281c6d4d8 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -813,6 +813,8 @@ DrawSwapReadbackResult::DrawResult LayerTreeHostImpl::CalculateRenderPasses(
 
     AppendQuadsData append_quads_data(target_render_pass_id);
 
+    DCHECK(it->transform_is_invertible()) << "Layer should not have been added"

[avallee, 2014/04/15 18:53:26]

I didn't see any place where it made sense to add a test to
layer_tree_host_impl_unittests, do you think there's one that makes sense?

[avallee, 2014/04/16 18:20:56]

Deleted this pending part 2.

+                                          << " to surface";
     if (it.represents_target_render_surface()) {
       if (it->HasCopyRequest()) {
         have_copy_request = true;