Remove parts of //cc we aren't using

cc/layers/render_surface.cc

Index: cc/layers/render_surface.cc
diff --git a/cc/layers/render_surface.cc b/cc/layers/render_surface.cc
deleted file mode 100644
index 35dde1008364416cc43956908963b0b13f4daa17..0000000000000000000000000000000000000000
--- a/cc/layers/render_surface.cc
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright 2010 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/layers/render_surface.h"
-
-#include "cc/base/math_util.h"
-#include "cc/layers/layer.h"
-#include "ui/gfx/transform.h"
-
-namespace cc {
-
-RenderSurface::RenderSurface(Layer* owning_layer)
-    : owning_layer_(owning_layer),
-      draw_opacity_(1),
-      draw_opacity_is_animating_(false),
-      target_surface_transforms_are_animating_(false),
-      screen_space_transforms_are_animating_(false),
-      is_clipped_(false),
-      contributes_to_drawn_surface_(false),
-      nearest_occlusion_immune_ancestor_(nullptr) {
-}
-
-RenderSurface::~RenderSurface() {
-  for (size_t i = 0; i < layer_list_.size(); ++i) {
-    DCHECK(!layer_list_.at(i)->render_surface()) <<
-        "RenderSurfaces should be cleared from the contributing layers " <<
-        "before destroying this surface to avoid leaking a circular " <<
-        "reference on the contributing layer. Probably the " <<
-        "RenderSurfaceLayerList should just be destroyed before destroying " <<
-        "any RenderSurfaces on layers.";
-  }
-}
-
-gfx::RectF RenderSurface::DrawableContentRect() const {
-  gfx::RectF drawable_content_rect =
-      MathUtil::MapClippedRect(draw_transform_, content_rect_);
-  if (owning_layer_->has_replica())
-    drawable_content_rect.Union(
-        MathUtil::MapClippedRect(replica_draw_transform_, content_rect_));
-  return drawable_content_rect;
-}
-
-void RenderSurface::ClearLayerLists() {
-  layer_list_.clear();
-}
-
-}  // namespace cc