cc: Replace Region with SimpleEnclosedRegion for occlusion tracking

cc/layers/layer.cc

 // 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/layer.h"
 
 #include <algorithm>
 
 #include "base/atomic_sequence_num.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
 #include "base/metrics/histogram.h"
 #include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_events.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/layer_animation_controller.h"
+#include "cc/base/simple_enclosed_region.h"
 #include "cc/layers/layer_client.h"
 #include "cc/layers/layer_impl.h"
 #include "cc/layers/scrollbar_layer_interface.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
 #include "ui/gfx/geometry/vector2d_conversions.h"
 #include "ui/gfx/rect_conversions.h"
@@ skipping 1142 matching lines @@
 void Layer::AddLayerAnimationEventObserver(
     LayerAnimationEventObserver* animation_observer) {
   layer_animation_controller_->AddEventObserver(animation_observer);
 }
 
 void Layer::RemoveLayerAnimationEventObserver(
     LayerAnimationEventObserver* animation_observer) {
   layer_animation_controller_->RemoveEventObserver(animation_observer);
 }
 
-Region Layer::VisibleContentOpaqueRegion() const {
+SimpleEnclosedRegion Layer::VisibleContentOpaqueRegion() const {
   if (contents_opaque())
-    return visible_content_rect();
-  return Region();
+    return SimpleEnclosedRegion(visible_content_rect());
+  return SimpleEnclosedRegion();
 }
 
 ScrollbarLayerInterface* Layer::ToScrollbarLayer() {
   return NULL;
 }
 
 RenderingStatsInstrumentation* Layer::rendering_stats_instrumentation() const {
   return layer_tree_host_->rendering_stats_instrumentation();
 }
 
@@ skipping 40 matching lines @@
 
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 bool Layer::HasDelegatedContent() const {
   return false;
 }
 
 }  // namespace cc