Stop displaying layers with non-invertible transforms.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 795 matching lines @@
        ++it) {
     RenderPass::Id target_render_pass_id =
         it.target_render_surface_layer()->render_surface()->RenderPassId();
     RenderPass* target_render_pass =
         frame->render_passes_by_id[target_render_pass_id];
 
     occlusion_tracker.EnterLayer(it);
 
     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;
         it->TakeCopyRequestsAndTransformToTarget(
             &target_render_pass->copy_requests);
       }
     } else if (it.represents_contributing_render_surface() &&
                it->render_surface()->contributes_to_drawn_surface()) {
       RenderPass::Id contributing_render_pass_id =
           it->render_surface()->RenderPassId();
@@ skipping 2275 matching lines @@
   swap_promise_monitor_.erase(monitor);
 }
 
 void LayerTreeHostImpl::NotifySwapPromiseMonitorsOfSetNeedsRedraw() {
   std::set<SwapPromiseMonitor*>::iterator it = swap_promise_monitor_.begin();
   for (; it != swap_promise_monitor_.end(); it++)
     (*it)->OnSetNeedsRedrawOnImpl();
 }
 
 }  // namespace cc