cc: Replace Region with SimpleEnclosedRegion for occlusion tracking

cc/layers/tiled_layer.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.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "build/build_config.h"
+#include "cc/base/simple_enclosed_region.h"
 #include "cc/layers/layer_impl.h"
 #include "cc/layers/tiled_layer_impl.h"
 #include "cc/resources/layer_updater.h"
 #include "cc/resources/prioritized_resource.h"
 #include "cc/resources/priority_calculator.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/occlusion_tracker.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "ui/gfx/rect_conversions.h"
 
@@ skipping 609 matching lines @@
       continue;
     gfx::Rect tile_rect = tiler_->TileRect(tile);
     SetPriorityForTexture(predicted_visible_rect_,
                           tile_rect,
                           draws_to_root,
                           small_animated_layer,
                           tile->managed_resource());
   }
 }
 
-Region TiledLayer::VisibleContentOpaqueRegion() const {
+SimpleEnclosedRegion TiledLayer::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 TiledLayer::ResetUpdateState() {
   skips_draw_ = false;
   failed_update_ = false;
 
   LayerTilingData::TileMap::const_iterator end = tiler_->tiles().end();
   for (LayerTilingData::TileMap::const_iterator iter = tiler_->tiles().begin();
        iter != end;
@@ skipping 234 matching lines @@
   gfx::Rect prepaint_rect = visible_content_rect();
   prepaint_rect.Inset(-tiler_->tile_size().width() * kPrepaintColumns,
                       -tiler_->tile_size().height() * kPrepaintRows);
   gfx::Rect content_rect(content_bounds());
   prepaint_rect.Intersect(content_rect);
 
   return prepaint_rect;
 }
 
 }  // namespace cc