cc: Add a flag to layers that returns true if the layer is in RSLL.

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 "base/debug/trace_event.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/animation/scrollbar_animation_controller_linear_fade.h"
@@ skipping 79 matching lines @@
       page_scale_delta_(1),
       sent_page_scale_delta_(1),
       min_page_scale_factor_(0),
       max_page_scale_factor_(0),
       scrolling_layer_id_from_previous_tree_(0),
       contents_textures_purged_(false),
       requires_high_res_to_draw_(false),
       viewport_size_invalid_(false),
       needs_update_draw_properties_(true),
       needs_full_tree_sync_(true),
-      next_activation_forces_redraw_(false) {}
+      next_activation_forces_redraw_(false),
+      calculate_draw_properties_count_(0u) {

[vmpstr, 2014/05/02 23:06:27]

There is a SourceAnimationFrameNumber, which happens to be used in unittests
only... I'm somewhat hesitant on relying on that, so I opted in using a separate
count. 

If that's not acceptable, then I will have to do a deeper investigation into
whether the SourceAnimationFrameNumber is really what I want here.

+}
 
 LayerTreeImpl::~LayerTreeImpl() {
   // Need to explicitly clear the tree prior to destroying this so that
   // the LayerTreeImpl pointer is still valid in the LayerImpl dtor.
   DCHECK(!root_layer_);
   DCHECK(layers_with_copy_output_request_.empty());
 }
 
 void LayerTreeImpl::Shutdown() { root_layer_.reset(); }
 
@@ skipping 339 matching lines @@
     TRACE_EVENT2("cc",
                  "LayerTreeImpl::UpdateDrawProperties",
                  "IsActive",
                  IsActiveTree(),
                  "SourceFrameNumber",
                  source_frame_number_);
     LayerImpl* page_scale_layer =
         page_scale_layer_ ? page_scale_layer_ : InnerViewportContainerLayer();
     bool can_render_to_separate_surface =
         !output_surface()->ForcedDrawToSoftwareDevice();
+    ++calculate_draw_properties_count_;
     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
         root_layer(),
         DrawViewportSize(),
         layer_tree_host_impl_->DrawTransform(),
         device_scale_factor(),
         total_page_scale_factor(),
         page_scale_layer,
         MaxTextureSize(),
         settings().can_use_lcd_text,
         can_render_to_separate_surface,
@@ skipping 13 matching lines @@
     // UpdateTilePriorities on layers that will be visible (and thus have valid
     // draw properties) and not because any ordering is required.
     typedef LayerIterator<LayerImpl> LayerIteratorType;
     LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
     for (LayerIteratorType it =
              LayerIteratorType::Begin(&render_surface_layer_list_);
          it != end;
          ++it) {
       if (!it.represents_itself())
         continue;
+
       LayerImpl* layer = *it;
+      layer->draw_properties().last_render_surface_list_membership_index =

[vmpstr, 2014/05/02 23:06:27]

I suspect this should happen in LayerTreeHostCommon::CalculateDrawProperties? Is
there a place where we iterate all of the render surface layer list in there? I
found one push back to the list, but the iterate iterates more than just the
list.

[danakj, 2014/05/02 23:09:24]

Right, the output of CalcDrawProps is the RSLL. If you set this on every layer
that you push into the list, then you'll have what you want.

+          calculate_draw_properties_count_;
 
       layer->UpdateTilePriorities();
-      if (layer->mask_layer())
+      if (layer->mask_layer()) {
+        layer->mask_layer()
+            ->draw_properties()
+            .last_render_surface_list_membership_index =
+            calculate_draw_properties_count_;
         layer->mask_layer()->UpdateTilePriorities();
-      if (layer->replica_layer() && layer->replica_layer()->mask_layer())
+      }
+      if (layer->replica_layer() && layer->replica_layer()->mask_layer()) {
+        layer->replica_layer()
+            ->mask_layer()
+            ->draw_properties()
+            .last_render_surface_list_membership_index =
+            calculate_draw_properties_count_;
         layer->replica_layer()->mask_layer()->UpdateTilePriorities();
+      }
     }
   }
 
   DCHECK(!needs_update_draw_properties_) <<
       "CalcDrawProperties should not set_needs_update_draw_properties()";
 }
 
 const LayerImplList& LayerTreeImpl::RenderSurfaceLayerList() const {
   // If this assert triggers, then the list is dirty.
   DCHECK(!needs_update_draw_properties_);
@@ skipping 468 matching lines @@
 const std::vector<LayerImpl*>& LayerTreeImpl::LayersWithCopyOutputRequest()
     const {
   // Only the active tree needs to know about layers with copy requests, as
   // they are aborted if not serviced during draw.
   DCHECK(IsActiveTree());
 
   return layers_with_copy_output_request_;
 }
 
 }  // namespace cc