cc: Replace LayerIterator with iterator that walks layer list and effect tree

cc/trees/layer_tree_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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <iterator>
 #include <limits>
 #include <set>
 
 #include "base/containers/adapters.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/base/devtools_instrumentation.h"
 #include "cc/base/histograms.h"
 #include "cc/base/math_util.h"
 #include "cc/base/synced_property.h"
 #include "cc/debug/traced_value.h"
 #include "cc/input/page_scale_animation.h"
 #include "cc/input/scrollbar_animation_controller.h"
+#include "cc/layers/effect_tree_layer_list_iterator.h"
 #include "cc/layers/heads_up_display_layer_impl.h"
 #include "cc/layers/layer.h"
-#include "cc/layers/layer_iterator.h"
 #include "cc/layers/layer_list_iterator.h"
 #include "cc/layers/render_surface_impl.h"
 #include "cc/layers/scrollbar_layer_impl_base.h"
 #include "cc/output/compositor_frame_sink.h"
 #include "cc/resources/ui_resource_request.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_common.h"
 #include "cc/trees/layer_tree_host_impl.h"
@@ skipping 1030 matching lines @@
 
   {
     TRACE_EVENT2("cc", "LayerTreeImpl::UpdateDrawProperties::Occlusion",
                  "IsActive", IsActiveTree(), "SourceFrameNumber",
                  source_frame_number_);
     OcclusionTracker occlusion_tracker(
         layer_list_[0]->GetRenderSurface()->content_rect());
     occlusion_tracker.set_minimum_tracking_size(
         settings().minimum_occlusion_tracking_size);
 
-    // LayerIterator is used here instead of CallFunctionForEveryLayer to only
-    // UpdateTilePriorities on layers that will be visible (and thus have valid
-    // draw properties) and not because any ordering is required.
-    LayerIterator end = LayerIterator::End(&render_surface_layer_list_);
-    for (LayerIterator it = LayerIterator::Begin(&render_surface_layer_list_);
-         it != end; ++it) {
+    for (EffectTreeLayerListIterator it(this);
+         it.state() != EffectTreeLayerListIterator::State::END; ++it) {
       occlusion_tracker.EnterLayer(it);
 
-      if (it.represents_itself()) {
-        it->draw_properties().occlusion_in_content_space =
-            occlusion_tracker.GetCurrentOcclusionForLayer(it->DrawTransform());
+      if (it.state() == EffectTreeLayerListIterator::State::LAYER) {
+        LayerImpl* layer = it.current_layer();
+        layer->draw_properties().occlusion_in_content_space =
+            occlusion_tracker.GetCurrentOcclusionForLayer(
+                layer->DrawTransform());
       }
 
-      if (it.represents_contributing_render_surface()) {
+      if (it.state() ==
+          EffectTreeLayerListIterator::State::CONTRIBUTING_SURFACE) {
         const RenderSurfaceImpl* occlusion_surface =
             occlusion_tracker.OcclusionSurfaceForContributingSurface();
         gfx::Transform draw_transform;
-        RenderSurfaceImpl* render_surface = it->GetRenderSurface();
+        RenderSurfaceImpl* render_surface = it.current_render_surface();
         if (occlusion_surface) {
           // We are calculating transform between two render surfaces. So, we
           // need to apply the surface contents scale at target and remove the
           // surface contents scale at source.
           property_trees()->GetToTarget(render_surface->TransformTreeIndex(),
                                         occlusion_surface->EffectTreeIndex(),
                                         &draw_transform);
           const EffectNode* effect_node = property_trees()->effect_tree.Node(
               render_surface->EffectTreeIndex());
           draw_property_utils::ConcatInverseSurfaceContentsScale(
               effect_node, &draw_transform);
         }
 
         Occlusion occlusion =
             occlusion_tracker.GetCurrentOcclusionForContributingSurface(
                 draw_transform);
         render_surface->set_occlusion_in_content_space(occlusion);
         // Masks are used to draw the contributing surface, so should have
         // the same occlusion as the surface (nothing inside the surface
         // occludes them).
         if (LayerImpl* mask = render_surface->MaskLayer()) {
           mask->draw_properties().occlusion_in_content_space =
               occlusion_tracker.GetCurrentOcclusionForContributingSurface(
-                  draw_transform * it->DrawTransform());
+                  draw_transform * render_surface->SurfaceScale());
         }
       }
 
       occlusion_tracker.LeaveLayer(it);
     }
 
     unoccluded_screen_space_region_ =
         occlusion_tracker.ComputeVisibleRegionInScreen(this);
   }
 
@@ skipping 337 matching lines @@
 bool LayerTreeImpl::create_low_res_tiling() const {
   return layer_tree_host_impl_->create_low_res_tiling();
 }
 
 void LayerTreeImpl::SetNeedsRedraw() {
   layer_tree_host_impl_->SetNeedsRedraw();
 }
 
 void LayerTreeImpl::GetAllPrioritizedTilesForTracing(
     std::vector<PrioritizedTile>* prioritized_tiles) const {
-  LayerIterator end = LayerIterator::End(&render_surface_layer_list_);
-  for (LayerIterator it = LayerIterator::Begin(&render_surface_layer_list_);
-       it != end; ++it) {
-    if (!it.represents_itself())
+  for (auto it = layer_list_.rbegin(); it != layer_list_.rend(); ++it) {
+    LayerImpl* layer_impl = *it;
+    if (!layer_impl->is_drawn_render_surface_layer_list_member())
       continue;
-    LayerImpl* layer_impl = *it;
     layer_impl->GetAllPrioritizedTilesForTracing(prioritized_tiles);
   }
 }
 
 void LayerTreeImpl::AsValueInto(base::trace_event::TracedValue* state) const {
   TracedValue::MakeDictIntoImplicitSnapshot(state, "cc::LayerTreeImpl", this);
   state->SetInteger("source_frame_number", source_frame_number_);
 
   state->BeginArray("render_surface_layer_list");
-  LayerIterator end = LayerIterator::End(&render_surface_layer_list_);
-  for (LayerIterator it = LayerIterator::Begin(&render_surface_layer_list_);
-       it != end; ++it) {
-    if (!it.represents_itself())
+  for (auto it = layer_list_.rbegin(); it != layer_list_.rend(); ++it) {
+    if (!(*it)->is_drawn_render_surface_layer_list_member())
       continue;
     TracedValue::AppendIDRef(*it, state);
   }
   state->EndArray();
 
   state->BeginArray("swap_promise_trace_ids");
   for (const auto& swap_promise : swap_promise_list_)
     state->AppendDouble(swap_promise->TraceId());
   state->EndArray();
 
@@ skipping 636 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc