Remove parts of //cc we aren't using

cc/trees/occlusion.cc

-// Copyright 2014 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/occlusion.h"
-
-#include "cc/base/math_util.h"
-#include "ui/gfx/geometry/rect.h"
-
-namespace cc {
-
-Occlusion::Occlusion() {
-}
-
-Occlusion::Occlusion(const gfx::Transform& draw_transform,
-                     const SimpleEnclosedRegion& occlusion_from_outside_target,
-                     const SimpleEnclosedRegion& occlusion_from_inside_target)
-    : draw_transform_(draw_transform),
-      occlusion_from_outside_target_(occlusion_from_outside_target),
-      occlusion_from_inside_target_(occlusion_from_inside_target) {
-}
-
-Occlusion Occlusion::GetOcclusionWithGivenDrawTransform(
-    const gfx::Transform& transform) const {
-  return Occlusion(
-      transform, occlusion_from_outside_target_, occlusion_from_inside_target_);
-}
-
-bool Occlusion::HasOcclusion() const {
-  return !occlusion_from_inside_target_.IsEmpty() ||
-         !occlusion_from_outside_target_.IsEmpty();
-}
-
-bool Occlusion::IsOccluded(const gfx::Rect& content_rect) const {
-  if (content_rect.IsEmpty())
-    return true;
-
-  if (!HasOcclusion())
-    return false;
-
-  gfx::Rect unoccluded_rect_in_target_surface =
-      GetUnoccludedRectInTargetSurface(content_rect);
-  return unoccluded_rect_in_target_surface.IsEmpty();
-}
-
-gfx::Rect Occlusion::GetUnoccludedContentRect(
-    const gfx::Rect& content_rect) const {
-  if (content_rect.IsEmpty())
-    return content_rect;
-
-  if (!HasOcclusion())
-    return content_rect;
-
-  gfx::Rect unoccluded_rect_in_target_surface =
-      GetUnoccludedRectInTargetSurface(content_rect);
-  if (unoccluded_rect_in_target_surface.IsEmpty())
-    return gfx::Rect();
-
-  gfx::Transform inverse_draw_transform(gfx::Transform::kSkipInitialization);
-  bool ok = draw_transform_.GetInverse(&inverse_draw_transform);
-  DCHECK(ok);
-
-  gfx::Rect unoccluded_rect = MathUtil::ProjectEnclosingClippedRect(
-      inverse_draw_transform, unoccluded_rect_in_target_surface);
-  unoccluded_rect.Intersect(content_rect);
-
-  return unoccluded_rect;
-}
-
-gfx::Rect Occlusion::GetUnoccludedRectInTargetSurface(
-    const gfx::Rect& content_rect) const {
-  // Take the ToEnclosingRect at each step, as we want to contain any unoccluded
-  // partial pixels in the resulting Rect.
-  gfx::Rect unoccluded_rect_in_target_surface =
-      MathUtil::MapEnclosingClippedRect(draw_transform_, content_rect);
-  DCHECK_LE(occlusion_from_inside_target_.GetRegionComplexity(), 1u);
-  DCHECK_LE(occlusion_from_outside_target_.GetRegionComplexity(), 1u);
-  // These subtract operations are more lossy than if we did both operations at
-  // once.
-  unoccluded_rect_in_target_surface.Subtract(
-      occlusion_from_inside_target_.bounds());
-  unoccluded_rect_in_target_surface.Subtract(
-      occlusion_from_outside_target_.bounds());
-
-  return unoccluded_rect_in_target_surface;
-}
-
-bool Occlusion::IsEqual(const Occlusion& other) const {
-  return draw_transform_ == other.draw_transform_ &&
-         occlusion_from_inside_target_ == other.occlusion_from_inside_target_ &&
-         occlusion_from_outside_target_ == other.occlusion_from_outside_target_;
-}
-
-std::string Occlusion::ToString() const {
-  return draw_transform_.ToString() + "outside(" +
-         occlusion_from_outside_target_.ToString() + ") inside(" +
-         occlusion_from_inside_target_.ToString() + ")";
-}
-
-}  // namespace cc