Keeping track of descendants that draw content instead of recalcualting

cc/layers/delegated_renderer_layer_impl_unittest.cc

 // Copyright 2012 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/layers/delegated_renderer_layer_impl.h"
 
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/layers/solid_color_layer_impl.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
@@ skipping 293 matching lines @@
   EXPECT_FALSE(delegated_renderer_layer_->render_surface());
 
   host_impl_->DrawLayers(&frame);
   host_impl_->DidDrawAllLayers(frame);
 }
 
 TEST_F(DelegatedRendererLayerImplTestSimple, DoesOwnARenderSurfaceForOpacity) {
   delegated_renderer_layer_->SetOpacity(0.5f);
 
   LayerTreeHostImpl::FrameData frame;
+  FakeLayerTreeHostImpl::UpdateNumChildrenAndDrawProperties(

[danakj, 2014/08/06 14:57:07]

PrepareToDraw does an UpdateDrawProperties, how come this test needs
UpdateNumChildrenAndDrawProps but the test below needs UpdateNumChildren only?

[awoloszyn, 2014/08/08 15:53:20]

I think the DrawProperties was overkill, I have changed to UpdadeNumChildren.

+      host_impl_->active_tree());
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // This test case has quads from multiple layers in the delegated renderer, so
   // if the DelegatedRendererLayer has opacity < 1, it should end up with a
   // render surface.
   EXPECT_TRUE(delegated_renderer_layer_->render_surface());
 
   host_impl_->DrawLayers(&frame);
   host_impl_->DidDrawAllLayers(frame);
 }
 
 TEST_F(DelegatedRendererLayerImplTestSimple,
        DoesOwnARenderSurfaceForTransform) {
   gfx::Transform rotation;
   rotation.RotateAboutZAxis(30.0);
   delegated_renderer_layer_->SetTransform(rotation);
 
   LayerTreeHostImpl::FrameData frame;
+  FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(
+      host_impl_->active_tree()->root_layer());
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // This test case has quads from multiple layers in the delegated renderer, so
   // if the DelegatedRendererLayer has opacity < 1, it should end up with a
   // render surface.
   EXPECT_TRUE(delegated_renderer_layer_->render_surface());
 
   host_impl_->DrawLayers(&frame);
   host_impl_->DidDrawAllLayers(frame);
 }
@@ skipping 1190 matching lines @@
   scoped_ptr<DelegatedRendererLayerImpl> other_layer =
       DelegatedRendererLayerImpl::Create(host_impl_->active_tree(), 6);
 
   delegated_renderer_layer_impl->PushPropertiesTo(other_layer.get());
 
   EXPECT_EQ(0.5f, other_layer->inverse_device_scale_factor());
 }
 
 }  // namespace
 }  // namespace cc