cc:: Layer with animating opacity should contribute to drawn surface

Right now, layer with animating opacity and opacity 0 draws but does not
contribute to drawn surface.
This patch also replaces screen_space_opacity_is_aniamting on the effect tree
with has_animated_opacity. We don't need to know screen space opacity animation
because even if some ancestor has animating opacity, the current layer need not
draw if has opacity 0 and itself doesn't animate opacity.

BUG=580940, 582021
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1649783004

Cr-Commit-Position: refs/heads/master@{#372397}

5 files changed, 30 insertions, 18 deletions

diff --git a/cc/proto/property_tree.proto b/cc/proto/property_tree.proto
index f70c8bd..713c60a 100644
--- a/cc/proto/property_tree.proto
+++ b/cc/proto/property_tree.proto
@@ -85,7 +85,7 @@ message EffectNodeData {
   optional bool has_copy_request = 4;
   optional bool has_background_filters = 5;
   optional bool is_drawn = 6;
-  optional bool screen_space_opacity_is_animating = 7;
+  optional bool has_animated_opacity = 7;
   optional int64 num_copy_requests_in_subtree = 8;
   optional int64 transform_id = 9;
   optional int64 clip_id = 10;
diff --git a/cc/trees/layer_tree_host_common_unittest.cc b/cc/trees/layer_tree_host_common_unittest.cc
index 84e7fde..50fbaa5 100644
--- a/cc/trees/layer_tree_host_common_unittest.cc
+++ b/cc/trees/layer_tree_host_common_unittest.cc
@@ -5188,7 +5188,7 @@ TEST_F(LayerTreeHostCommonTest, OpacityAnimatingOnPendingTree) {
 
   // If the root itself is hidden, the child should not be drawn even if it has
   // an animating opacity.
-  root->SetOpacity(0.f);
+  root->SetOpacity(0.0f);
   root->layer_tree_impl()->property_trees()->needs_rebuild = true;
   LayerImplList render_surface_layer_list2;
   root->layer_tree_impl()->IncrementRenderSurfaceListIdForTesting();
@@ -5202,6 +5202,25 @@ TEST_F(LayerTreeHostCommonTest, OpacityAnimatingOnPendingTree) {
   EffectTree tree = root->layer_tree_impl()->property_trees()->effect_tree;
   EffectNode* node = tree.Node(child_ptr->effect_tree_index());
   EXPECT_FALSE(node->data.is_drawn);
+
+  // A layer should be drawn and it should contribute to drawn surface when
+  // it has animating opacity even if it has opacity 0.
+  root->SetOpacity(1.0f);
+  child_ptr->SetOpacity(0.0f);
+  root->layer_tree_impl()->property_trees()->needs_rebuild = true;
+  LayerImplList render_surface_layer_list3;
+  root->layer_tree_impl()->IncrementRenderSurfaceListIdForTesting();
+  LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs3(
+      root.get(), root->bounds(), &render_surface_layer_list3,
+      root->layer_tree_impl()->current_render_surface_list_id());
+  inputs3.can_adjust_raster_scales = true;
+  LayerTreeHostCommon::CalculateDrawProperties(&inputs3);
+
+  child_ptr = root->layer_tree_impl()->LayerById(2);
+  tree = root->layer_tree_impl()->property_trees()->effect_tree;
+  node = tree.Node(child_ptr->effect_tree_index());
+  EXPECT_TRUE(node->data.is_drawn);
+  EXPECT_TRUE(tree.ContributesToDrawnSurface(child_ptr->effect_tree_index()));
 }
 
 class LayerTreeSettingsForLCDTextTest : public LayerTreeSettings {
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index 2f88c83..a425efa 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -422,7 +422,7 @@ EffectNodeData::EffectNodeData()
       has_copy_request(false),
       has_background_filters(false),
       is_drawn(true),
-      screen_space_opacity_is_animating(false),
+      has_animated_opacity(false),
       num_copy_requests_in_subtree(0),
       transform_id(0),
       clip_id(0) {}
@@ -434,8 +434,7 @@ bool EffectNodeData::operator==(const EffectNodeData& other) const {
          has_copy_request == other.has_copy_request &&
          has_background_filters == other.has_background_filters &&
          is_drawn == other.is_drawn &&
-         screen_space_opacity_is_animating ==
-             other.screen_space_opacity_is_animating &&
+         has_animated_opacity == other.has_animated_opacity &&
          num_copy_requests_in_subtree == other.num_copy_requests_in_subtree &&
          transform_id == other.transform_id && clip_id == other.clip_id;
 }
@@ -449,8 +448,7 @@ void EffectNodeData::ToProtobuf(proto::TreeNode* proto) const {
   data->set_has_copy_request(has_copy_request);
   data->set_has_background_filters(has_background_filters);
   data->set_is_drawn(is_drawn);
-  data->set_screen_space_opacity_is_animating(
-      screen_space_opacity_is_animating);
+  data->set_has_animated_opacity(has_animated_opacity);
   data->set_num_copy_requests_in_subtree(num_copy_requests_in_subtree);
   data->set_transform_id(transform_id);
   data->set_clip_id(clip_id);
@@ -466,7 +464,7 @@ void EffectNodeData::FromProtobuf(const proto::TreeNode& proto) {
   has_copy_request = data.has_copy_request();
   has_background_filters = data.has_background_filters();
   is_drawn = data.is_drawn();
-  screen_space_opacity_is_animating = data.screen_space_opacity_is_animating();
+  has_animated_opacity = data.has_animated_opacity();
   num_copy_requests_in_subtree = data.num_copy_requests_in_subtree();
   transform_id = data.transform_id();
   clip_id = data.clip_id();
@@ -1103,9 +1101,7 @@ void EffectTree::UpdateIsDrawn(EffectNode* node, EffectNode* parent_node) {
   //    drawn irrespective of their opacity.
   if (node->data.has_copy_request || node->data.has_background_filters)
     node->data.is_drawn = true;
-  else if (node->data.screen_space_opacity_is_animating)
-    node->data.is_drawn = parent_node ? parent_node->data.is_drawn : true;
-  else if (node->data.opacity == 0.f)
+  else if (node->data.opacity == 0.f && !node->data.has_animated_opacity)
     node->data.is_drawn = false;
   else if (parent_node)
     node->data.is_drawn = parent_node->data.is_drawn;
@@ -1137,7 +1133,8 @@ bool EffectTree::ContributesToDrawnSurface(int id) {
   EffectNode* parent_node = parent(node);
   bool contributes_to_drawn_surface =
       node->data.is_drawn &&
-      (node->data.opacity != 0.f || node->data.has_background_filters);
+      (node->data.opacity != 0.f || node->data.has_animated_opacity ||
+       node->data.has_background_filters);
   if (parent_node && !parent_node->data.is_drawn)
     contributes_to_drawn_surface = false;
   return contributes_to_drawn_surface;
diff --git a/cc/trees/property_tree.h b/cc/trees/property_tree.h
index 52aa419..f419e5f 100644
--- a/cc/trees/property_tree.h
+++ b/cc/trees/property_tree.h
@@ -251,7 +251,7 @@ struct CC_EXPORT EffectNodeData {
   bool has_copy_request;
   bool has_background_filters;
   bool is_drawn;
-  bool screen_space_opacity_is_animating;
+  bool has_animated_opacity;
   int num_copy_requests_in_subtree;
   int transform_id;
   int clip_id;
diff --git a/cc/trees/property_tree_builder.cc b/cc/trees/property_tree_builder.cc
index 0dc9e13..7319c6e 100644
--- a/cc/trees/property_tree_builder.cc
+++ b/cc/trees/property_tree_builder.cc
@@ -603,6 +603,7 @@ bool AddEffectNodeIfNeeded(
   node.data.has_render_surface = should_create_render_surface;
   node.data.has_copy_request = layer->HasCopyRequest();
   node.data.has_background_filters = !layer->background_filters().IsEmpty();
+  node.data.has_animated_opacity = has_animated_opacity;
 
   if (!is_root) {
     // The effect node's transform id is used only when we create a render
@@ -616,10 +617,6 @@ bool AddEffectNodeIfNeeded(
           data_from_ancestor.transform_tree->next_available_id();
     }
     node.data.clip_id = data_from_ancestor.clip_tree_parent;
-
-    EffectNode* parent = data_from_ancestor.effect_tree->Node(parent_id);
-    node.data.screen_space_opacity_is_animating =
-        parent->data.screen_space_opacity_is_animating || has_animated_opacity;
   } else {
     // Root render surface acts the unbounded and untransformed to draw content
     // into. Transform node created from root layer (includes device scale
@@ -627,7 +624,6 @@ bool AddEffectNodeIfNeeded(
     // to root render surface's content, but not root render surface itself.
     node.data.transform_id = kRootPropertyTreeNodeId;
     node.data.clip_id = kRootPropertyTreeNodeId;
-    node.data.screen_space_opacity_is_animating = has_animated_opacity;
   }
   data_for_children->effect_tree_parent =
       data_for_children->effect_tree->Insert(node, parent_id);