Revert of cc: Remove tile sharing from tilings.

cc/resources/tiling_set_raster_queue_all.h

 // 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.
 
 #ifndef CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_
 #define CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_
 
-#include "base/containers/stack_container.h"
 #include "cc/base/cc_export.h"
 #include "cc/resources/picture_layer_tiling_set.h"
 #include "cc/resources/tile.h"
 #include "cc/resources/tile_priority.h"
 
 namespace cc {
 
 // This queue returns all tiles required to be rasterized from HIGH_RESOLUTION
 // and LOW_RESOLUTION tilings.
 class CC_EXPORT TilingSetRasterQueueAll {
@@ skipping 39 matching lines @@
    public:
     VisibleTilingIterator() = default;
     VisibleTilingIterator(PictureLayerTiling* tiling, TilingData* tiling_data);
 
     VisibleTilingIterator& operator++();
 
    private:
     TilingData::Iterator iterator_;
   };
 
-  class PendingVisibleTilingIterator : public OnePriorityRectIterator {
-   public:
-    PendingVisibleTilingIterator() = default;
-    PendingVisibleTilingIterator(PictureLayerTiling* tiling,
-                                 TilingData* tiling_data);
-
-    PendingVisibleTilingIterator& operator++();
-
-   private:
-    TilingData::DifferenceIterator iterator_;
-  };
-
   // Iterates over skewport only, spiral around the visible rect.
   class SkewportTilingIterator : public OnePriorityRectIterator {
    public:
     SkewportTilingIterator() = default;
     SkewportTilingIterator(PictureLayerTiling* tiling, TilingData* tiling_data);
 
     SkewportTilingIterator& operator++();
 
    private:
     TilingData::SpiralDifferenceIterator iterator_;
-    gfx::Rect pending_visible_rect_;
   };
 
   // Iterates over soon border only, spiral around the visible rect.
   class SoonBorderTilingIterator : public OnePriorityRectIterator {
    public:
     SoonBorderTilingIterator() = default;
     SoonBorderTilingIterator(PictureLayerTiling* tiling,
                              TilingData* tiling_data);
 
     SoonBorderTilingIterator& operator++();
 
    private:
     TilingData::SpiralDifferenceIterator iterator_;
-    gfx::Rect pending_visible_rect_;
   };
 
   // Iterates over eventually rect only, spiral around the soon rect.
   class EventuallyTilingIterator : public OnePriorityRectIterator {
    public:
     EventuallyTilingIterator() = default;
     EventuallyTilingIterator(PictureLayerTiling* tiling,
                              TilingData* tiling_data);
 
     EventuallyTilingIterator& operator++();
 
    private:
     TilingData::SpiralDifferenceIterator iterator_;
-    gfx::Rect pending_visible_rect_;
   };
 
   // Iterates over all of the above phases in the following order: visible,
   // skewport, soon border, eventually.
   class TilingIterator {
    public:
     TilingIterator();
     explicit TilingIterator(PictureLayerTiling* tiling,
                             TilingData* tiling_data);
-    ~TilingIterator();
+    ~TilingIterator() = default;
 
     bool done() const { return current_tile_ == nullptr; }
     const Tile* operator*() const { return current_tile_; }
     Tile* operator*() { return current_tile_; }
     TilePriority::PriorityBin type() const {
       switch (phase_) {
         case VISIBLE_RECT:
           return TilePriority::NOW;
-        case PENDING_VISIBLE_RECT:
         case SKEWPORT_RECT:
         case SOON_BORDER_RECT:
           return TilePriority::SOON;
         case EVENTUALLY_RECT:
           return TilePriority::EVENTUALLY;
       }
       NOTREACHED();
       return TilePriority::EVENTUALLY;
     }
 
     TilingIterator& operator++();
 
    private:
-    // PENDING VISIBLE RECT refers to the visible rect that will become current
-    // upon activation (ie, the pending tree's visible rect). Tiles in this
-    // region that are not part of the current visible rect are all handled
-    // here. Note that when processing a pending tree, this rect is the same as
-    // the visible rect so no tiles are processed in this case.
     enum Phase {
       VISIBLE_RECT,
-      PENDING_VISIBLE_RECT,
       SKEWPORT_RECT,
       SOON_BORDER_RECT,
       EVENTUALLY_RECT
     };
 
     void AdvancePhase();
 
     PictureLayerTiling* tiling_;
     TilingData* tiling_data_;
 
     Phase phase_;
 
     Tile* current_tile_;
     VisibleTilingIterator visible_iterator_;
-    PendingVisibleTilingIterator pending_visible_iterator_;
     SkewportTilingIterator skewport_iterator_;
     SoonBorderTilingIterator soon_border_iterator_;
     EventuallyTilingIterator eventually_iterator_;
   };
 
-  enum IteratorType {
-    LOW_RES,
-    HIGH_RES,
-    ACTIVE_NON_IDEAL_PENDING_HIGH_RES,
-    NUM_ITERATORS
-  };
+  enum IteratorType { LOW_RES, HIGH_RES, NUM_ITERATORS };
 
   void AdvanceToNextStage();
 
   PictureLayerTilingSet* tiling_set_;
 
   struct IterationStage {
-    IterationStage(IteratorType type, TilePriority::PriorityBin bin);
     IteratorType iterator_type;
     TilePriority::PriorityBin tile_type;
   };
 
   size_t current_stage_;
 
-  // The max number of stages is 6: 1 low res, 3 high res, and 2 active non
-  // ideal pending high res.
-  base::StackVector<IterationStage, 6> stages_;
+  // One low res stage, and three high res stages.
+  IterationStage stages_[4];
   TilingIterator iterators_[NUM_ITERATORS];
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILING_SET_RASTER_QUEUE_ALL_H_