cc: Remove support for disabling non-root render surfaces.

cc/trees/layer_tree_host_common.cc

Index: cc/trees/layer_tree_host_common.cc
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index d9c71941f4fdcc034b1b3e09049ed62fb5d3176f..302ac236a15a3bbe47e32e5ccf8545def80d509a 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -78,7 +78,6 @@ LayerTreeHostCommon::CalcDrawPropsImplInputs::CalcDrawPropsImplInputs(
     const gfx::Vector2dF& elastic_overscroll,
     const LayerImpl* elastic_overscroll_application_layer,
     int max_texture_size,
-    bool can_render_to_separate_surface,
     bool can_adjust_raster_scales,
     bool verify_clip_tree_calculations,
     bool verify_visible_rect_calculations,
@@ -96,7 +95,6 @@ LayerTreeHostCommon::CalcDrawPropsImplInputs::CalcDrawPropsImplInputs(
       elastic_overscroll_application_layer(
           elastic_overscroll_application_layer),
       max_texture_size(max_texture_size),
-      can_render_to_separate_surface(can_render_to_separate_surface),
       can_adjust_raster_scales(can_adjust_raster_scales),
       verify_clip_tree_calculations(verify_clip_tree_calculations),
       verify_visible_rect_calculations(verify_visible_rect_calculations),
@@ -120,7 +118,6 @@ LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting::
                               gfx::Vector2dF(),
                               NULL,
                               std::numeric_limits<int>::max() / 2,
-                              true,
                               false,
                               true,
                               true,
@@ -285,8 +282,7 @@ enum PropertyTreeOption {
 static void ComputeInitialRenderSurfaceLayerList(
     LayerTreeImpl* layer_tree_impl,
     PropertyTrees* property_trees,
-    LayerImplList* render_surface_layer_list,
-    bool can_render_to_separate_surface) {
+    LayerImplList* render_surface_layer_list) {
   // Add all non-skipped surfaces to the initial render surface layer list. Add
   // all non-skipped layers to the layer list of their target surface, and
   // add their content rect to their target surface's accumulated content rect.
@@ -305,9 +301,7 @@ static void ComputeInitialRenderSurfaceLayerList(
     if (skip_layer)
       continue;
 
-    bool render_to_separate_surface =
-        is_root || (can_render_to_separate_surface && layer->render_surface());
-
+    bool render_to_separate_surface = is_root || layer->render_surface();
     if (render_to_separate_surface) {
       DCHECK(layer->render_surface());
       DCHECK(layer->render_target() == layer->render_surface());
@@ -434,7 +428,6 @@ static void CalculateRenderSurfaceLayerList(
     LayerTreeImpl* layer_tree_impl,
     PropertyTrees* property_trees,
     LayerImplList* render_surface_layer_list,
-    const bool can_render_to_separate_surface,
     const int max_texture_size) {
   // This calculates top level Render Surface Layer List, and Layer List for all
   // Render Surfaces.
@@ -446,8 +439,7 @@ static void CalculateRenderSurfaceLayerList(
   // have an empty content rect. After surface content rects are computed,
   // produce a final RSLL that omits empty surfaces.
   ComputeInitialRenderSurfaceLayerList(layer_tree_impl, property_trees,
-                                       &initial_render_surface_list,
-                                       can_render_to_separate_surface);
+                                       &initial_render_surface_list);
   ComputeSurfaceContentRects(layer_tree_impl, property_trees,
                              &initial_render_surface_list, max_texture_size);
   ComputeListOfNonEmptySurfaces(layer_tree_impl, property_trees,
@@ -482,8 +474,8 @@ void CalculateDrawPropertiesInternal(
           inputs->elastic_overscroll_application_layer,
           inputs->elastic_overscroll, inputs->page_scale_factor,
           inputs->device_scale_factor, gfx::Rect(inputs->device_viewport_size),
-          inputs->device_transform, inputs->can_render_to_separate_surface,
-          inputs->property_trees, &visible_layer_list);
+          inputs->device_transform, inputs->property_trees,
+          &visible_layer_list);
 
       // Property trees are normally constructed on the main thread and
       // passed to compositor thread. Source to parent updates on them are not
@@ -528,8 +520,7 @@ void CalculateDrawPropertiesInternal(
           inputs->device_scale_factor, page_scale_factor_for_root,
           inputs->device_transform, inputs->root_layer->position());
       draw_property_utils::ComputeVisibleRects(
-          inputs->root_layer, inputs->property_trees,
-          inputs->can_render_to_separate_surface, &visible_layer_list);
+          inputs->root_layer, inputs->property_trees, &visible_layer_list);
       break;
     }
   }
@@ -539,8 +530,6 @@ void CalculateDrawPropertiesInternal(
                        "LayerTreeHostCommon::CalculateDrawProperties");
   }
 
-  DCHECK(inputs->can_render_to_separate_surface ==
-         inputs->property_trees->non_root_surfaces_enabled);
   for (LayerImpl* layer : visible_layer_list) {
     draw_property_utils::ComputeLayerDrawProperties(layer,
                                                     inputs->property_trees);
@@ -548,8 +537,7 @@ void CalculateDrawPropertiesInternal(
 
   CalculateRenderSurfaceLayerList(
       inputs->root_layer->layer_tree_impl(), inputs->property_trees,
-      inputs->render_surface_layer_list, inputs->can_render_to_separate_surface,
-      inputs->max_texture_size);
+      inputs->render_surface_layer_list, inputs->max_texture_size);
 
   if (inputs->verify_clip_tree_calculations)
     draw_property_utils::VerifyClipTreeCalculations(visible_layer_list,
@@ -571,7 +559,6 @@ void CalculateDrawPropertiesInternal(
 void LayerTreeHostCommon::CalculateDrawPropertiesForTesting(
     CalcDrawPropsMainInputsForTesting* inputs) {
   LayerList update_layer_list;
-  bool can_render_to_separate_surface = true;
   PropertyTrees* property_trees =
       inputs->root_layer->layer_tree_host()->property_trees();
   Layer* overscroll_elasticity_layer = nullptr;
@@ -583,8 +570,7 @@ void LayerTreeHostCommon::CalculateDrawPropertiesForTesting(
       inputs->page_scale_factor, inputs->device_scale_factor,
       gfx::Rect(inputs->device_viewport_size), inputs->device_transform,
       property_trees);
-  draw_property_utils::UpdatePropertyTrees(property_trees,
-                                           can_render_to_separate_surface);
+  draw_property_utils::UpdatePropertyTrees(property_trees);
   draw_property_utils::FindLayersThatNeedUpdates(
       inputs->root_layer->layer_tree_host(), property_trees,
       &update_layer_list);