Revert of cc: Remove tile sharing from tilings.

cc/resources/tiling_set_raster_queue_all.cc

Index: cc/resources/tiling_set_raster_queue_all.cc
diff --git a/cc/resources/tiling_set_raster_queue_all.cc b/cc/resources/tiling_set_raster_queue_all.cc
index cd3a4f90df5bd42881205230bf2eefa0c0d0301c..2ccba67eeb31e637ff39644507d23e1c0bf83d31 100644
--- a/cc/resources/tiling_set_raster_queue_all.cc
+++ b/cc/resources/tiling_set_raster_queue_all.cc
@@ -11,12 +11,6 @@
 #include "cc/resources/tile_priority.h"
 
 namespace cc {
-
-TilingSetRasterQueueAll::IterationStage::IterationStage(
-    IteratorType type,
-    TilePriority::PriorityBin bin)
-    : iterator_type(type), tile_type(bin) {
-}
 
 TilingSetRasterQueueAll::TilingSetRasterQueueAll(
     PictureLayerTilingSet* tiling_set,
@@ -25,73 +19,39 @@
   DCHECK(tiling_set_);
 
   // Early out if the tiling set has no tilings.
-  if (!tiling_set_->num_tilings())
-    return;
-
-  const PictureLayerTilingClient* client = tiling_set->client();
-  WhichTree tree = client->GetTree();
+  if (!tiling_set_->num_tilings()) {
+    current_stage_ = arraysize(stages_);
+    return;
+  }
+
   // Find high and low res tilings and initialize the iterators.
-  PictureLayerTiling* high_res_tiling = nullptr;
-  PictureLayerTiling* low_res_tiling = nullptr;
-  // This variable would point to a tiling that has a NON_IDEAL_RESOLUTION
-  // resolution on the active tree, but HIGH_RESOLUTION on the pending tree.
-  // These tilings are the only non-ideal tilings that could have required for
-  // activation tiles, so they need to be considered for rasterization.
-  PictureLayerTiling* active_non_ideal_pending_high_res_tiling = nullptr;
   for (size_t i = 0; i < tiling_set_->num_tilings(); ++i) {
     PictureLayerTiling* tiling = tiling_set_->tiling_at(i);
     if (tiling->resolution() == HIGH_RESOLUTION)
-      high_res_tiling = tiling;
+      iterators_[HIGH_RES] = TilingIterator(tiling, &tiling->tiling_data_);
     if (prioritize_low_res && tiling->resolution() == LOW_RESOLUTION)
-      low_res_tiling = tiling;
-    if (tree == ACTIVE_TREE && tiling->resolution() == NON_IDEAL_RESOLUTION) {
-      const PictureLayerTiling* twin =
-          client->GetPendingOrActiveTwinTiling(tiling);
-      if (twin && twin->resolution() == HIGH_RESOLUTION)
-        active_non_ideal_pending_high_res_tiling = tiling;
-    }
-  }
-
-  bool use_low_res_tiling = low_res_tiling && low_res_tiling->has_tiles();
-  if (use_low_res_tiling && prioritize_low_res) {
-    iterators_[LOW_RES] =
-        TilingIterator(low_res_tiling, &low_res_tiling->tiling_data_);
-    stages_->push_back(IterationStage(LOW_RES, TilePriority::NOW));
-  }
-
-  DCHECK(high_res_tiling);
-  bool use_high_res_tiling = high_res_tiling->has_tiles();
-  if (use_high_res_tiling) {
-    iterators_[HIGH_RES] =
-        TilingIterator(high_res_tiling, &high_res_tiling->tiling_data_);
-    stages_->push_back(IterationStage(HIGH_RES, TilePriority::NOW));
-  }
-
-  if (low_res_tiling && !prioritize_low_res) {
-    iterators_[LOW_RES] =
-        TilingIterator(low_res_tiling, &low_res_tiling->tiling_data_);
-    stages_->push_back(IterationStage(LOW_RES, TilePriority::NOW));
-  }
-
-  if (active_non_ideal_pending_high_res_tiling &&
-      active_non_ideal_pending_high_res_tiling->has_tiles()) {
-    iterators_[ACTIVE_NON_IDEAL_PENDING_HIGH_RES] =
-        TilingIterator(active_non_ideal_pending_high_res_tiling,
-                       &active_non_ideal_pending_high_res_tiling->tiling_data_);
-
-    stages_->push_back(
-        IterationStage(ACTIVE_NON_IDEAL_PENDING_HIGH_RES, TilePriority::NOW));
-    stages_->push_back(
-        IterationStage(ACTIVE_NON_IDEAL_PENDING_HIGH_RES, TilePriority::SOON));
-  }
-
-  if (use_high_res_tiling) {
-    stages_->push_back(IterationStage(HIGH_RES, TilePriority::SOON));
-    stages_->push_back(IterationStage(HIGH_RES, TilePriority::EVENTUALLY));
-  }
-
-  if (stages_->empty())
-    return;
+      iterators_[LOW_RES] = TilingIterator(tiling, &tiling->tiling_data_);
+  }
+
+  if (prioritize_low_res) {
+    stages_[0].iterator_type = LOW_RES;
+    stages_[0].tile_type = TilePriority::NOW;
+
+    stages_[1].iterator_type = HIGH_RES;
+    stages_[1].tile_type = TilePriority::NOW;
+  } else {
+    stages_[0].iterator_type = HIGH_RES;
+    stages_[0].tile_type = TilePriority::NOW;
+
+    stages_[1].iterator_type = LOW_RES;
+    stages_[1].tile_type = TilePriority::NOW;
+  }
+
+  stages_[2].iterator_type = HIGH_RES;
+  stages_[2].tile_type = TilePriority::SOON;
+
+  stages_[3].iterator_type = HIGH_RES;
+  stages_[3].tile_type = TilePriority::EVENTUALLY;
 
   IteratorType index = stages_[current_stage_].iterator_type;
   TilePriority::PriorityBin tile_type = stages_[current_stage_].tile_type;
@@ -103,7 +63,7 @@
 }
 
 bool TilingSetRasterQueueAll::IsEmpty() const {
-  return current_stage_ >= stages_->size();
+  return current_stage_ >= arraysize(stages_);
 }
 
 void TilingSetRasterQueueAll::Pop() {
@@ -140,9 +100,9 @@
 }
 
 void TilingSetRasterQueueAll::AdvanceToNextStage() {
-  DCHECK_LT(current_stage_, stages_->size());
+  DCHECK_LT(current_stage_, arraysize(stages_));
   ++current_stage_;
-  while (current_stage_ < stages_->size()) {
+  while (current_stage_ < arraysize(stages_)) {
     IteratorType index = stages_[current_stage_].iterator_type;
     TilePriority::PriorityBin tile_type = stages_[current_stage_].tile_type;
 
@@ -213,33 +173,11 @@
   return *this;
 }
 
-// PendingVisibleTilingIterator.
-TilingSetRasterQueueAll::PendingVisibleTilingIterator::
-    PendingVisibleTilingIterator(PictureLayerTiling* tiling,
-                                 TilingData* tiling_data)
-    : OnePriorityRectIterator(tiling, tiling_data) {
-  iterator_ = TilingData::DifferenceIterator(tiling_data_,
-                                             tiling_->pending_visible_rect(),
-                                             tiling_->current_visible_rect());
-  if (!iterator_)
-    return;
-  if (!GetFirstTileAndCheckIfValid(&iterator_))
-    ++(*this);
-}
-
-TilingSetRasterQueueAll::PendingVisibleTilingIterator&
-    TilingSetRasterQueueAll::PendingVisibleTilingIterator::
-    operator++() {
-  AdvanceToNextTile(&iterator_);
-  return *this;
-}
-
 // SkewportTilingIterator.
 TilingSetRasterQueueAll::SkewportTilingIterator::SkewportTilingIterator(
     PictureLayerTiling* tiling,
     TilingData* tiling_data)
-    : OnePriorityRectIterator(tiling, tiling_data),
-      pending_visible_rect_(tiling->pending_visible_rect()) {
+    : OnePriorityRectIterator(tiling, tiling_data) {
   if (!tiling_->has_skewport_rect_tiles())
     return;
   iterator_ = TilingData::SpiralDifferenceIterator(
@@ -247,11 +185,7 @@
       tiling_->current_visible_rect(), tiling_->current_visible_rect());
   if (!iterator_)
     return;
-  if (!GetFirstTileAndCheckIfValid(&iterator_)) {
-    ++(*this);
-    return;
-  }
-  if (tile_->content_rect().Intersects(pending_visible_rect_))
+  if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }
 
@@ -259,11 +193,6 @@
     TilingSetRasterQueueAll::SkewportTilingIterator::
     operator++() {
   AdvanceToNextTile(&iterator_);
-  while (!done()) {
-    if (!tile_->content_rect().Intersects(pending_visible_rect_))
-      break;
-    AdvanceToNextTile(&iterator_);
-  }
   return *this;
 }
 
@@ -271,8 +200,7 @@
 TilingSetRasterQueueAll::SoonBorderTilingIterator::SoonBorderTilingIterator(
     PictureLayerTiling* tiling,
     TilingData* tiling_data)
-    : OnePriorityRectIterator(tiling, tiling_data),
-      pending_visible_rect_(tiling->pending_visible_rect()) {
+    : OnePriorityRectIterator(tiling, tiling_data) {
   if (!tiling_->has_soon_border_rect_tiles())
     return;
   iterator_ = TilingData::SpiralDifferenceIterator(
@@ -280,11 +208,7 @@
       tiling_->current_skewport_rect(), tiling_->current_visible_rect());
   if (!iterator_)
     return;
-  if (!GetFirstTileAndCheckIfValid(&iterator_)) {
-    ++(*this);
-    return;
-  }
-  if (tile_->content_rect().Intersects(pending_visible_rect_))
+  if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }
 
@@ -292,11 +216,6 @@
     TilingSetRasterQueueAll::SoonBorderTilingIterator::
     operator++() {
   AdvanceToNextTile(&iterator_);
-  while (!done()) {
-    if (!tile_->content_rect().Intersects(pending_visible_rect_))
-      break;
-    AdvanceToNextTile(&iterator_);
-  }
   return *this;
 }
 
@@ -304,8 +223,7 @@
 TilingSetRasterQueueAll::EventuallyTilingIterator::EventuallyTilingIterator(
     PictureLayerTiling* tiling,
     TilingData* tiling_data)
-    : OnePriorityRectIterator(tiling, tiling_data),
-      pending_visible_rect_(tiling->pending_visible_rect()) {
+    : OnePriorityRectIterator(tiling, tiling_data) {
   if (!tiling_->has_eventually_rect_tiles())
     return;
   iterator_ = TilingData::SpiralDifferenceIterator(
@@ -313,11 +231,7 @@
       tiling_->current_skewport_rect(), tiling_->current_soon_border_rect());
   if (!iterator_)
     return;
-  if (!GetFirstTileAndCheckIfValid(&iterator_)) {
-    ++(*this);
-    return;
-  }
-  if (tile_->content_rect().Intersects(pending_visible_rect_))
+  if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }
 
@@ -325,11 +239,6 @@
     TilingSetRasterQueueAll::EventuallyTilingIterator::
     operator++() {
   AdvanceToNextTile(&iterator_);
-  while (!done()) {
-    if (!tile_->content_rect().Intersects(pending_visible_rect_))
-      break;
-    AdvanceToNextTile(&iterator_);
-  }
   return *this;
 }
 
@@ -353,9 +262,6 @@
   current_tile_ = *visible_iterator_;
 }
 
-TilingSetRasterQueueAll::TilingIterator::~TilingIterator() {
-}
-
 void TilingSetRasterQueueAll::TilingIterator::AdvancePhase() {
   DCHECK_LT(phase_, EVENTUALLY_RECT);
 
@@ -366,12 +272,6 @@
       case VISIBLE_RECT:
         NOTREACHED();
         return;
-      case PENDING_VISIBLE_RECT:
-        pending_visible_iterator_ =
-            PendingVisibleTilingIterator(tiling_, tiling_data_);
-        if (!pending_visible_iterator_.done())
-          current_tile_ = *pending_visible_iterator_;
-        break;
       case SKEWPORT_RECT:
         skewport_iterator_ = SkewportTilingIterator(tiling_, tiling_data_);
         if (!skewport_iterator_.done())
@@ -403,14 +303,6 @@
       }
       current_tile_ = *visible_iterator_;
       break;
-    case PENDING_VISIBLE_RECT:
-      ++pending_visible_iterator_;
-      if (pending_visible_iterator_.done()) {
-        AdvancePhase();
-        return *this;
-      }
-      current_tile_ = *pending_visible_iterator_;
-      break;
     case SKEWPORT_RECT:
       ++skewport_iterator_;
       if (skewport_iterator_.done()) {