cc: Make LayerTreeTests use a DelegatingRenderer and Display.

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 779 matching lines @@
   // If the root render surface has no visible damage, then don't generate a
   // frame at all.
   RenderSurfaceImpl* root_surface = active_tree_->RootRenderSurface();
   bool root_surface_has_no_visible_damage =
       !root_surface->damage_tracker()->current_damage_rect().Intersects(
           root_surface->content_rect());
   bool root_surface_has_contributing_layers =
       !root_surface->layer_list().empty();
   bool hud_wants_to_draw_ = active_tree_->hud_layer() &&
                             active_tree_->hud_layer()->IsAnimatingHUDContents();
+  bool resources_must_be_resent =
+      output_surface_->capabilities().can_force_reclaim_resources;
   if (root_surface_has_contributing_layers &&
       root_surface_has_no_visible_damage &&
       !active_tree_->property_trees()->effect_tree.HasCopyRequests() &&
-      !output_surface_->capabilities().can_force_reclaim_resources &&
-      !hud_wants_to_draw_) {
+      !resources_must_be_resent && !hud_wants_to_draw_) {
     TRACE_EVENT0("cc",
                  "LayerTreeHostImpl::CalculateRenderPasses::EmptyDamageRect");
     frame->has_no_damage = true;
     DCHECK(!resourceless_software_draw_);
     return DRAW_SUCCESS;
   }
 
   TRACE_EVENT_BEGIN2(
       "cc", "LayerTreeHostImpl::CalculateRenderPasses",
       "render_surface_layer_list.size()",
@@ skipping 3227 matching lines @@
   return task_runner_provider_->HasImplThread();
 }
 
 bool LayerTreeHostImpl::CommitToActiveTree() const {
   // In single threaded mode we skip the pending tree and commit directly to the
   // active tree.
   return !task_runner_provider_->HasImplThread();
 }
 
 }  // namespace cc