cc: Add CHECKS to diagnose invalid property tree indices on impl thread.

cc/trees/layer_tree_host.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.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 23 matching lines @@
 #include "cc/base/math_util.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/input/layer_selection_bound.h"
 #include "cc/input/page_scale_animation.h"
 #include "cc/layers/heads_up_display_layer.h"
 #include "cc/layers/heads_up_display_layer_impl.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/painted_scrollbar_layer.h"
 #include "cc/resources/ui_resource_manager.h"
 #include "cc/tiles/frame_viewer_instrumentation.h"
+#include "cc/trees/clip_node.h"
 #include "cc/trees/draw_property_utils.h"
 #include "cc/trees/effect_node.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_common.h"
 #include "cc/trees/layer_tree_host_impl.h"
 #include "cc/trees/mutator_host.h"
 #include "cc/trees/property_tree_builder.h"
 #include "cc/trees/proxy_main.h"
+#include "cc/trees/scroll_node.h"
 #include "cc/trees/single_thread_proxy.h"
 #include "cc/trees/swap_promise_manager.h"
 #include "cc/trees/transform_node.h"
 #include "cc/trees/tree_synchronizer.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/geometry/vector2d_conversions.h"
 
 namespace {
 static base::StaticAtomicSequenceNumber s_layer_tree_host_sequence_number;
 }
@@ skipping 288 matching lines @@
     sync_tree->UpdatePropertyTreeScrollingAndAnimationFromMainThread(
         is_impl_side_update);
 
     TRACE_EVENT0("cc", "LayerTreeHostInProcess::AnimationHost::PushProperties");
     DCHECK(host_impl->mutator_host());
     mutator_host_->PushPropertiesTo(host_impl->mutator_host());
 
     sync_tree->lifecycle().AdvanceTo(LayerTreeLifecycle::kNotSyncing);
   }
 
+  // Temporary check to debug crbug.com/726423. The property tree indices on the
+  // LayerTree should be valid after the PropertyTree update above.
+  for (auto* layer_impl : *sync_tree) {
+    CHECK(layer_impl);
+    CHECK(sync_tree->property_trees()->transform_tree.Node(
+        layer_impl->transform_tree_index()));
+    CHECK(sync_tree->property_trees()->clip_tree.Node(
+        layer_impl->clip_tree_index()));
+    CHECK(sync_tree->property_trees()->effect_tree.Node(
+        layer_impl->effect_tree_index()));
+    CHECK(sync_tree->property_trees()->scroll_tree.Node(
+        layer_impl->scroll_tree_index()));
+  }
+
   // Transfer image decode requests to the impl thread.
   for (auto& request : queued_image_decodes_)
     host_impl->QueueImageDecode(std::move(request.first), request.second);
   queued_image_decodes_.clear();
 
   micro_benchmark_controller_.ScheduleImplBenchmarks(host_impl);
   property_trees_.ResetAllChangeTracking();
 }
 
 void LayerTreeHost::PushPropertyTreesTo(LayerTreeImpl* tree_impl) {
@@ skipping 351 matching lines @@
       TRACE_EVENT_INSTANT1(
           "cc", "LayerTreeHostInProcess::UpdateLayers_BuiltPropertyTrees",
           TRACE_EVENT_SCOPE_THREAD, "property_trees",
           property_trees->AsTracedValue());
     } else {
       TRACE_EVENT_INSTANT1(
           "cc", "LayerTreeHostInProcess::UpdateLayers_ReceivedPropertyTrees",
           TRACE_EVENT_SCOPE_THREAD, "property_trees",
           property_trees->AsTracedValue());
     }
+
+    // Temporary check to debug crbug.com/726423. The property tree indices on
+    // the LayerTreeImpl should be valid after all state synchronization has
+    // finished.
+    for (auto* layer : *this) {
+      CHECK(property_trees_.transform_tree.Node(layer->transform_tree_index()));
+      CHECK(property_trees_.clip_tree.Node(layer->clip_tree_index()));
+      CHECK(property_trees_.effect_tree.Node(layer->effect_tree_index()));
+      CHECK(property_trees_.scroll_tree.Node(layer->scroll_tree_index()));
+    }
+
     draw_property_utils::UpdatePropertyTrees(this, property_trees);
     draw_property_utils::FindLayersThatNeedUpdates(this, property_trees,
                                                    &update_layer_list);
   }
 
   bool content_is_suitable_for_gpu = true;
   bool did_paint_content =
       PaintContent(update_layer_list, &content_is_suitable_for_gpu);
 
   if (content_is_suitable_for_gpu) {
@@ skipping 718 matching lines @@
 
 void LayerTreeHost::SetHasCopyRequest(bool has_copy_request) {
   has_copy_request_ = has_copy_request;
 }
 
 void LayerTreeHost::RequestBeginMainFrameNotExpected(bool new_state) {
   proxy_->RequestBeginMainFrameNotExpected(new_state);
 }
 
 }  // namespace cc