cc: Replace Region with SimpleEnclosedRegion for occlusion tracking

cc/layers/tiled_layer_impl.cc

 // Copyright 2011 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/tiled_layer_impl.h"
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/strings/stringprintf.h"
 #include "cc/base/math_util.h"
+#include "cc/base/simple_enclosed_region.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/quads/checkerboard_draw_quad.h"
 #include "cc/quads/debug_border_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/tile_draw_quad.h"
 #include "cc/resources/layer_tiling_data.h"
 #include "cc/trees/occlusion_tracker.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/skia/include/core/SkColor.h"
@@ skipping 273 matching lines @@
 
 void TiledLayerImpl::PushInvalidTile(int i, int j) {
   DrawableTile* tile = TileAt(i, j);
   if (!tile)
     tile = CreateTile(i, j);
   tile->set_resource_id(0);
   tile->set_opaque_rect(gfx::Rect());
   tile->set_contents_swizzled(false);
 }
 
-Region TiledLayerImpl::VisibleContentOpaqueRegion() const {
+SimpleEnclosedRegion TiledLayerImpl::VisibleContentOpaqueRegion() const {
   if (skips_draw_)
-    return Region();
+    return SimpleEnclosedRegion();
   if (contents_opaque())
-    return visible_content_rect();
+    return SimpleEnclosedRegion(visible_content_rect());
   return tiler_->OpaqueRegionInContentRect(visible_content_rect());
 }
 
 void TiledLayerImpl::ReleaseResources() {
   tiler_->reset();
 }
 
 const char* TiledLayerImpl::LayerTypeAsString() const {
   return "cc::TiledLayerImpl";
 }
 
 }  // namespace cc