Remove scroll_clip_layer dependency from viewport layer tracking

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>
@@ skipping 63 matching lines @@
     : layer_tree_host_impl_(layer_tree_host_impl),
       source_frame_number_(-1),
       is_first_frame_after_commit_tracker_(-1),
       root_layer_for_testing_(nullptr),
       hud_layer_(nullptr),
       background_color_(0),
       has_transparent_background_(false),
       last_scrolled_scroll_node_index_(ScrollTree::kInvalidNodeId),
       overscroll_elasticity_layer_id_(Layer::INVALID_ID),
       page_scale_layer_id_(Layer::INVALID_ID),
+      inner_viewport_container_layer_id_(Layer::INVALID_ID),
+      outer_viewport_container_layer_id_(Layer::INVALID_ID),
       inner_viewport_scroll_layer_id_(Layer::INVALID_ID),
       outer_viewport_scroll_layer_id_(Layer::INVALID_ID),
       page_scale_factor_(page_scale_factor),
       min_page_scale_factor_(0),
       max_page_scale_factor_(0),
       device_scale_factor_(1.f),
       painted_device_scale_factor_(1.f),
       content_source_id_(0),
       elastic_overscroll_(elastic_overscroll),
       layers_(new OwnedLayerImplList),
@@ skipping 56 matching lines @@
   if (!LayerListIsEmpty()) {
     LayerTreeHostCommon::CallFunctionForEveryLayer(
         this, [](LayerImpl* layer) { layer->RecreateTileResources(); });
   }
 }
 
 bool LayerTreeImpl::IsViewportLayerId(int id) const {
 #if DCHECK_IS_ON()
   // Ensure the LayerImpl viewport layer types correspond to the LayerTreeImpl's
   // viewport layers.
+  if (id == inner_viewport_container_layer_id_)
+    DCHECK(LayerById(id)->viewport_layer_type() == INNER_VIEWPORT_CONTAINER);
+  if (id == outer_viewport_container_layer_id_)
+    DCHECK(LayerById(id)->viewport_layer_type() == OUTER_VIEWPORT_CONTAINER);
   if (id == inner_viewport_scroll_layer_id_)
     DCHECK(LayerById(id)->viewport_layer_type() == INNER_VIEWPORT_SCROLL);
   if (id == outer_viewport_scroll_layer_id_)
     DCHECK(LayerById(id)->viewport_layer_type() == OUTER_VIEWPORT_SCROLL);
-  if (InnerViewportContainerLayer() &&
-      id == InnerViewportContainerLayer()->id())
-    DCHECK(InnerViewportContainerLayer()->viewport_layer_type() ==
-           INNER_VIEWPORT_CONTAINER);
-  if (OuterViewportContainerLayer() &&
-      id == OuterViewportContainerLayer()->id())
-    DCHECK(OuterViewportContainerLayer()->viewport_layer_type() ==
-           OUTER_VIEWPORT_CONTAINER);
 #endif
   if (auto* layer = LayerById(id))
     return layer->viewport_layer_type() != NOT_VIEWPORT_LAYER;
   return false;
 }
 
 void LayerTreeImpl::DidUpdateScrollOffset(int layer_id) {
   DidUpdateScrollState(layer_id);
   DCHECK(lifecycle().AllowsPropertyTreeAccess());
   TransformTree& transform_tree = property_trees()->transform_tree;
@@ skipping 266 matching lines @@
   target_tree->set_browser_controls_shrink_blink_size(
       browser_controls_shrink_blink_size_);
   target_tree->set_top_controls_height(top_controls_height_);
   target_tree->set_bottom_controls_height(bottom_controls_height_);
   target_tree->PushBrowserControls(nullptr);
 
   // The page scale factor update can affect scrolling which requires that
   // these ids are set, so this must be before PushPageScaleFactorAndLimits.
   target_tree->SetViewportLayersFromIds(
       overscroll_elasticity_layer_id_, page_scale_layer_id_,
+      inner_viewport_container_layer_id_, outer_viewport_container_layer_id_,
       inner_viewport_scroll_layer_id_, outer_viewport_scroll_layer_id_);
 
   // Active tree already shares the page_scale_factor object with pending
   // tree so only the limits need to be provided.
   target_tree->PushPageScaleFactorAndLimits(nullptr, min_page_scale_factor(),
                                             max_page_scale_factor());
   target_tree->SetDeviceScaleFactor(device_scale_factor());
   target_tree->set_painted_device_scale_factor(painted_device_scale_factor());
   target_tree->SetRasterColorSpace(raster_color_space_);
   target_tree->elastic_overscroll()->PushPendingToActive();
@@ skipping 175 matching lines @@
 void LayerTreeImpl::SetFilterMutated(ElementId element_id,
                                      const FilterOperations& filters) {
   DCHECK_EQ(
       1u, property_trees()->element_id_to_effect_node_index.count(element_id));
   element_id_to_filter_animations_[element_id] = filters;
   if (property_trees()->effect_tree.OnFilterAnimated(element_id, filters))
     set_needs_update_draw_properties();
 }
 
 LayerImpl* LayerTreeImpl::InnerViewportContainerLayer() const {
-  return InnerViewportScrollLayer()
-             ? InnerViewportScrollLayer()->scroll_clip_layer()
-             : NULL;
+  return LayerById(inner_viewport_container_layer_id_);
 }
 
 LayerImpl* LayerTreeImpl::OuterViewportContainerLayer() const {
-  return OuterViewportScrollLayer()
-             ? OuterViewportScrollLayer()->scroll_clip_layer()
-             : NULL;
+  return LayerById(outer_viewport_container_layer_id_);
 }
 
 ScrollNode* LayerTreeImpl::CurrentlyScrollingNode() {
   DCHECK(IsActiveTree());
   return property_trees_.scroll_tree.CurrentlyScrollingNode();
 }
 
 const ScrollNode* LayerTreeImpl::CurrentlyScrollingNode() const {
   return property_trees_.scroll_tree.CurrentlyScrollingNode();
 }
@@ skipping 329 matching lines @@
 
   if (layer_list_.empty())
     return;
 
   property_trees()->scroll_tree.ApplySentScrollDeltasFromAbortedCommit();
 }
 
 void LayerTreeImpl::SetViewportLayersFromIds(
     int overscroll_elasticity_layer_id,
     int page_scale_layer_id,
+    int inner_viewport_container_layer_id,
+    int outer_viewport_container_layer_id,
     int inner_viewport_scroll_layer_id,
     int outer_viewport_scroll_layer_id) {
   overscroll_elasticity_layer_id_ = overscroll_elasticity_layer_id;
   page_scale_layer_id_ = page_scale_layer_id;
+  inner_viewport_container_layer_id_ = inner_viewport_container_layer_id;
+  outer_viewport_container_layer_id_ = outer_viewport_container_layer_id;
   inner_viewport_scroll_layer_id_ = inner_viewport_scroll_layer_id;
   outer_viewport_scroll_layer_id_ = outer_viewport_scroll_layer_id;
 
-  // The scroll_clip_layer Layer properties should be up-to-date.
-  DCHECK(lifecycle().AllowsLayerPropertyAccess());
-  if (auto* inner_scroll = LayerById(inner_viewport_scroll_layer_id_)) {
+  if (auto* inner_container = LayerById(inner_viewport_container_layer_id_))
+    inner_container->SetViewportLayerType(INNER_VIEWPORT_CONTAINER);
+  if (auto* inner_scroll = LayerById(inner_viewport_scroll_layer_id_))
     inner_scroll->SetViewportLayerType(INNER_VIEWPORT_SCROLL);
-    if (auto* inner_container = inner_scroll->scroll_clip_layer())
-      inner_container->SetViewportLayerType(INNER_VIEWPORT_CONTAINER);
-  }
-  if (auto* outer_scroll = LayerById(outer_viewport_scroll_layer_id_)) {
+  if (auto* outer_container = LayerById(outer_viewport_container_layer_id_))
+    outer_container->SetViewportLayerType(OUTER_VIEWPORT_CONTAINER);
+  if (auto* outer_scroll = LayerById(outer_viewport_scroll_layer_id_))
     outer_scroll->SetViewportLayerType(OUTER_VIEWPORT_SCROLL);
-    if (auto* outer_container = outer_scroll->scroll_clip_layer())
-      outer_container->SetViewportLayerType(OUTER_VIEWPORT_CONTAINER);
-  }
 }
 
 void LayerTreeImpl::ClearViewportLayers() {
   SetViewportLayersFromIds(Layer::INVALID_ID, Layer::INVALID_ID,
+                           Layer::INVALID_ID, Layer::INVALID_ID,
                            Layer::INVALID_ID, Layer::INVALID_ID);
 }
 
 // For unit tests, we use the layer's id as its element id.
 static void SetElementIdForTesting(LayerImpl* layer) {
   layer->SetElementId(LayerIdToElementIdForTesting(layer->id()));
 }
 
 void LayerTreeImpl::SetElementIdsForTesting() {
   LayerListIterator<LayerImpl> it(root_layer_for_testing_);
@@ skipping 1094 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