Track occlusion per tree on Tile.

cc/resources/tile.h

 // Copyright 2012 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.
 
 #ifndef CC_RESOURCES_TILE_H_
 #define CC_RESOURCES_TILE_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
@@ skipping 110 matching lines @@
   RasterMode DetermineOverallRasterMode() const;
 
   // Functionality used in tests.
   RasterMode GetRasterModeForTesting() const {
     return managed_state().raster_mode;
   }
   ManagedTileState::TileVersion& GetTileVersionForTesting(RasterMode mode) {
     return managed_state_.tile_versions[mode];
   }
 
-  void set_is_occluded(bool is_occluded) { is_occluded_ = is_occluded; }
-  bool is_occluded() const { return is_occluded_; }
+  void set_is_occluded(WhichTree tree, bool is_occluded) {
+    switch (tree) {
+      case ACTIVE_TREE:
+        is_occluded_on_active_tree_ = is_occluded;
+        break;
+      case PENDING_TREE:
+        is_occluded_on_pending_tree_ = is_occluded;
+        break;
+      default:

[danakj, 2014/07/07 19:26:29]

don't use default: for enums, then we don't get compiler warnings when we add
another value to the enum. Instead, make each case above return, and just
NOTREACHED() below the switch.

+        NOTREACHED();
+        return;
+    }
+  }
+
+  bool is_occluded(WhichTree tree) const {
+    switch (tree) {
+      case ACTIVE_TREE:
+        return is_occluded_on_active_tree_;

[enne (OOO), 2014/07/07 19:49:31]

Should is_occluded just go on TilePriority so you could say
priority_[ACTIVE_TREE].is_occluded?

[danakj, 2014/07/07 20:08:04]

FWIW, she did that originally but with vlad's new work this seems a little up in
the air. So in the interest of working parallelly, this adds a second bool while
deferring the decision about priority or not.

+      case PENDING_TREE:
+        return is_occluded_on_pending_tree_;
+      default:
+        NOTREACHED();

[danakj, 2014/07/07 19:26:29]

remove default: move this below the switch

or alternatively you could do is_occluded_[NUM_TREES] and have set/get just do
an array index with the tree variable. (like priority_)

[jbedley, 2014/07/07 20:25:13]

Done.

+        return false;
+    }
+  }
 
  private:
   friend class TileManager;
   friend class PrioritizedTileSet;
   friend class FakeTileManager;
   friend class BinComparator;
   friend class FakePictureLayerImpl;
 
   // Methods called by by tile manager.
   Tile(TileManager* tile_manager,
@@ skipping 10 matching lines @@
   ManagedTileState& managed_state() { return managed_state_; }
   const ManagedTileState& managed_state() const { return managed_state_; }
   RasterMode DetermineRasterModeForResolution(TileResolution resolution) const;
 
   TileManager* tile_manager_;
   scoped_refptr<PicturePileImpl> picture_pile_;
   gfx::Rect tile_size_;
   gfx::Rect content_rect_;
   float contents_scale_;
   gfx::Rect opaque_rect_;
-  bool is_occluded_;
+  bool is_occluded_on_active_tree_;
+  bool is_occluded_on_pending_tree_;
 
   TilePriority priority_[NUM_TREES];
   ManagedTileState managed_state_;
   int layer_id_;
   int source_frame_number_;
   int flags_;
 
   Id id_;
   static Id s_next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Tile);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILE_H_