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

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 3398897d0848339d43b22a90a3776404078d6877..ad8ee377f4a0add3c1f15b725927a58fffa9d9cf 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -987,10 +987,6 @@ bool LayerTreeImpl::UpdateDrawProperties(
     TRACE_EVENT2(
         "cc", "LayerTreeImpl::UpdateDrawProperties::CalculateDrawProperties",
         "IsActive", IsActiveTree(), "SourceFrameNumber", source_frame_number_);
-    // TODO(crbug.com/692780): Remove this option entirely once this get to
-    // stable and proves it works.
-    bool can_render_to_separate_surface = true;
-
     // We verify visible rect calculations whenever we verify clip tree
     // calculations except when this function is explicitly passed a flag asking
     // us to skip it.
@@ -1005,7 +1001,6 @@ bool LayerTreeImpl::UpdateDrawProperties(
         InnerViewportScrollLayer(), OuterViewportScrollLayer(),
         elastic_overscroll()->Current(IsActiveTree()),
         OverscrollElasticityLayer(), resource_provider()->max_texture_size(),
-        can_render_to_separate_surface,
         settings().layer_transforms_should_scale_layer_contents,
         settings().verify_clip_tree_calculations,
         verify_visible_rect_calculations,