cc: Start using raster/eviction iterators in tile manager

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index e569410e7631f923cfa00b1fa31511f8d80f0578..69ca52fa681444907032ed61262b30dd89506874 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -227,110 +227,6 @@ class ImageDecodeTaskImpl : public ImageDecodeTask {
 
 const size_t kScheduledRasterTasksLimit = 32u;
 
-// Memory limit policy works by mapping some bin states to the NEVER bin.
-const ManagedTileBin kBinPolicyMap[NUM_TILE_MEMORY_LIMIT_POLICIES][NUM_BINS] = {
-    // [ALLOW_NOTHING]
-    {NEVER_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NEVER_BIN,  // [NOW_BIN]
-     NEVER_BIN,  // [SOON_BIN]
-     NEVER_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     NEVER_BIN,  // [EVENTUALLY_BIN]
-     NEVER_BIN,  // [AT_LAST_AND_ACTIVE_BIN]
-     NEVER_BIN,  // [AT_LAST_BIN]
-     NEVER_BIN   // [NEVER_BIN]
-    },
-    // [ALLOW_ABSOLUTE_MINIMUM]
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     NEVER_BIN,                  // [SOON_BIN]
-     NEVER_BIN,                  // [EVENTUALLY_AND_ACTIVE_BIN]
-     NEVER_BIN,                  // [EVENTUALLY_BIN]
-     NEVER_BIN,                  // [AT_LAST_AND_ACTIVE_BIN]
-     NEVER_BIN,                  // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    },
-    // [ALLOW_PREPAINT_ONLY]
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     NEVER_BIN,                  // [EVENTUALLY_AND_ACTIVE_BIN]
-     NEVER_BIN,                  // [EVENTUALLY_BIN]
-     NEVER_BIN,                  // [AT_LAST_AND_ACTIVE_BIN]
-     NEVER_BIN,                  // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    },
-    // [ALLOW_ANYTHING]
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     EVENTUALLY_BIN,             // [EVENTUALLY_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_AND_ACTIVE_BIN]
-     AT_LAST_BIN,                // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    }};
-
-// Ready to draw works by mapping NOW_BIN to NOW_AND_READY_TO_DRAW_BIN.
-const ManagedTileBin kBinReadyToDrawMap[2][NUM_BINS] = {
-    // Not ready
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     EVENTUALLY_BIN,             // [EVENTUALLY_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_AND_ACTIVE_BIN]
-     AT_LAST_BIN,                // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    },
-    // Ready
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_AND_READY_TO_DRAW_BIN,  // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     EVENTUALLY_BIN,             // [EVENTUALLY_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_AND_ACTIVE_BIN]
-     AT_LAST_BIN,                // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    }};
-
-// Active works by mapping some bin stats to equivalent _ACTIVE_BIN state.
-const ManagedTileBin kBinIsActiveMap[2][NUM_BINS] = {
-    // Inactive
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     EVENTUALLY_BIN,             // [EVENTUALLY_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_AND_ACTIVE_BIN]
-     AT_LAST_BIN,                // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    },
-    // Active
-    {NOW_AND_READY_TO_DRAW_BIN,  // [NOW_AND_READY_TO_DRAW_BIN]
-     NOW_BIN,                    // [NOW_BIN]
-     SOON_BIN,                   // [SOON_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_AND_ACTIVE_BIN]
-     EVENTUALLY_AND_ACTIVE_BIN,  // [EVENTUALLY_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_AND_ACTIVE_BIN]
-     AT_LAST_AND_ACTIVE_BIN,     // [AT_LAST_BIN]
-     NEVER_BIN                   // [NEVER_BIN]
-    }};
-
-// Determine bin based on three categories of tiles: things we need now,
-// things we need soon, and eventually.
-inline ManagedTileBin BinFromTilePriority(const TilePriority& prio) {
-  if (prio.priority_bin == TilePriority::NOW)
-    return NOW_BIN;
-
-  if (prio.priority_bin == TilePriority::SOON)
-    return SOON_BIN;
-
-  if (prio.distance_to_visible == std::numeric_limits<float>::infinity())
-    return NEVER_BIN;
-
-  return EVENTUALLY_BIN;
-}
-
 }  // namespace
 
 RasterTaskCompletionStats::RasterTaskCompletionStats()
@@ -368,13 +264,10 @@ TileManager::TileManager(
       task_runner_(task_runner),
       resource_pool_(resource_pool),
       rasterizer_(rasterizer),
-      prioritized_tiles_dirty_(false),
       all_tiles_that_need_to_be_rasterized_have_memory_(true),
-      all_tiles_required_for_activation_have_memory_(true),
-      memory_required_bytes_(0),
-      memory_nice_to_have_bytes_(0),
       bytes_releasable_(0),
       resources_releasable_(0),
+      bytes_required_but_not_allocated_(0),
       ever_exceeded_memory_budget_(false),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       did_initialize_visible_tile_(false),
@@ -408,14 +301,9 @@ TileManager::~TileManager() {
 }
 
 void TileManager::Release(Tile* tile) {
-  prioritized_tiles_dirty_ = true;
   released_tiles_.push_back(tile);
 }
 
-void TileManager::DidChangeTilePriority(Tile* tile) {
-  prioritized_tiles_dirty_ = true;
-}
-
 bool TileManager::ShouldForceTasksRequiredForActivationToComplete() const {
   return global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 }
@@ -449,17 +337,6 @@ void TileManager::CleanUpReleasedTiles() {
   released_tiles_.clear();
 }
 
-void TileManager::UpdatePrioritizedTileSetIfNeeded() {
-  if (!prioritized_tiles_dirty_)
-    return;
-
-  CleanUpReleasedTiles();
-
-  prioritized_tiles_.Clear();
-  GetTilesWithAssignedBins(&prioritized_tiles_);
-  prioritized_tiles_dirty_ = false;
-}
-
 void TileManager::DidFinishRunningTasks() {
   TRACE_EVENT0("cc", "TileManager::DidFinishRunningTasks");
 
@@ -476,8 +353,7 @@ void TileManager::DidFinishRunningTasks() {
   did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   TileVector tiles_that_need_to_be_rasterized;
-  AssignGpuMemoryToTiles(&prioritized_tiles_,
-                         &tiles_that_need_to_be_rasterized);
+  AssignGpuMemoryToTiles(&tiles_that_need_to_be_rasterized);
 
   // |tiles_that_need_to_be_rasterized| will be empty when we reach a
   // steady memory state. Keep scheduling tasks until we reach this state.
@@ -518,150 +394,18 @@ void TileManager::DidFinishRunningTasks() {
 }
 
 void TileManager::DidFinishRunningTasksRequiredForActivation() {
-  // This is only a true indication that all tiles required for
-  // activation are initialized when no tiles are OOM. We need to
-  // wait for DidFinishRunningTasks() to be called, try to re-assign
-  // memory and in worst case use on-demand raster when tiles
-  // required for activation are OOM.
-  if (!all_tiles_required_for_activation_have_memory_)
-    return;
-
   ready_to_activate_check_notifier_.Schedule();
 }
 
-void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
-  TRACE_EVENT0("cc", "TileManager::GetTilesWithAssignedBins");
-
-  // Compute new stats to be return by GetMemoryStats().
-  memory_required_bytes_ = 0;
-  memory_nice_to_have_bytes_ = 0;
-
-  const TileMemoryLimitPolicy memory_policy = global_state_.memory_limit_policy;
-  const TreePriority tree_priority = global_state_.tree_priority;
-
-  // For each tree, bin into different categories of tiles.
-  for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
-    Tile* tile = it->second;
-    ManagedTileState& mts = tile->managed_state();
-
-    const ManagedTileState::TileVersion& tile_version =
-        tile->GetTileVersionForDrawing();
-    bool tile_is_ready_to_draw = tile_version.IsReadyToDraw();
-    bool tile_is_active = tile_is_ready_to_draw ||
-                          mts.tile_versions[mts.raster_mode].raster_task_;
-
-    // Get the active priority and bin.
-    TilePriority active_priority = tile->priority(ACTIVE_TREE);
-    ManagedTileBin active_bin = BinFromTilePriority(active_priority);
-
-    // Get the pending priority and bin.
-    TilePriority pending_priority = tile->priority(PENDING_TREE);
-    ManagedTileBin pending_bin = BinFromTilePriority(pending_priority);
-
-    bool pending_is_low_res = pending_priority.resolution == LOW_RESOLUTION;
-    bool pending_is_non_ideal =
-        pending_priority.resolution == NON_IDEAL_RESOLUTION;
-    bool active_is_non_ideal =
-        active_priority.resolution == NON_IDEAL_RESOLUTION;
-
-    // Adjust bin state based on if ready to draw.
-    active_bin = kBinReadyToDrawMap[tile_is_ready_to_draw][active_bin];
-    pending_bin = kBinReadyToDrawMap[tile_is_ready_to_draw][pending_bin];
-
-    // Adjust bin state based on if active.
-    active_bin = kBinIsActiveMap[tile_is_active][active_bin];
-    pending_bin = kBinIsActiveMap[tile_is_active][pending_bin];
-
-    // We never want to paint new non-ideal tiles, as we always have
-    // a high-res tile covering that content (paint that instead).
-    if (!tile_is_ready_to_draw && active_is_non_ideal)
-      active_bin = NEVER_BIN;
-    if (!tile_is_ready_to_draw && pending_is_non_ideal)
-      pending_bin = NEVER_BIN;
-
-    if (!tile_is_ready_to_draw || tile_version.requires_resource()) {
-      // The bin that the tile would have if the GPU memory manager had
-      // a maximally permissive policy, send to the GPU memory manager
-      // to determine policy.
-      ManagedTileBin gpu_memmgr_stats_bin = std::min(active_bin, pending_bin);
-      if ((gpu_memmgr_stats_bin == NOW_BIN) ||
-          (gpu_memmgr_stats_bin == NOW_AND_READY_TO_DRAW_BIN))
-        memory_required_bytes_ += BytesConsumedIfAllocated(tile);
-      if (gpu_memmgr_stats_bin != NEVER_BIN)
-        memory_nice_to_have_bytes_ += BytesConsumedIfAllocated(tile);
-    }
-
-    ManagedTileBin tree_bin[NUM_TREES];
-    tree_bin[ACTIVE_TREE] = kBinPolicyMap[memory_policy][active_bin];
-    tree_bin[PENDING_TREE] = kBinPolicyMap[memory_policy][pending_bin];
-
-    // Adjust pending bin state for low res tiles. This prevents pending tree
-    // low-res tiles from being initialized before high-res tiles.
-    if (pending_is_low_res)
-      tree_bin[PENDING_TREE] = std::max(tree_bin[PENDING_TREE], EVENTUALLY_BIN);
-
-    TilePriority tile_priority;
-    switch (tree_priority) {
-      case SAME_PRIORITY_FOR_BOTH_TREES:
-        mts.bin = std::min(tree_bin[ACTIVE_TREE], tree_bin[PENDING_TREE]);
-        tile_priority = tile->combined_priority();
-        break;
-      case SMOOTHNESS_TAKES_PRIORITY:
-        mts.bin = tree_bin[ACTIVE_TREE];
-        tile_priority = active_priority;
-        break;
-      case NEW_CONTENT_TAKES_PRIORITY:
-        mts.bin = tree_bin[PENDING_TREE];
-        tile_priority = pending_priority;
-        break;
-    }
-
-    // Bump up the priority if we determined it's NEVER_BIN on one tree,
-    // but is still required on the other tree.
-    bool is_in_never_bin_on_both_trees = tree_bin[ACTIVE_TREE] == NEVER_BIN &&
-                                         tree_bin[PENDING_TREE] == NEVER_BIN;
-
-    if (mts.bin == NEVER_BIN && !is_in_never_bin_on_both_trees)
-      mts.bin = tile_is_active ? AT_LAST_AND_ACTIVE_BIN : AT_LAST_BIN;
-
-    mts.resolution = tile_priority.resolution;
-    mts.priority_bin = tile_priority.priority_bin;
-    mts.distance_to_visible = tile_priority.distance_to_visible;
-    mts.required_for_activation = tile_priority.required_for_activation;
-
-    mts.visible_and_ready_to_draw =
-        tree_bin[ACTIVE_TREE] == NOW_AND_READY_TO_DRAW_BIN;
-
-    // Tiles that are required for activation shouldn't be in NEVER_BIN unless
-    // smoothness takes priority or memory policy allows nothing to be
-    // initialized.
-    DCHECK(!mts.required_for_activation || mts.bin != NEVER_BIN ||
-           tree_priority == SMOOTHNESS_TAKES_PRIORITY ||
-           memory_policy == ALLOW_NOTHING);
-
-    // If the tile is in NEVER_BIN and it does not have an active task, then we
-    // can release the resources early. If it does have the task however, we
-    // should keep it in the prioritized tile set to ensure that AssignGpuMemory
-    // can visit it.
-    if (mts.bin == NEVER_BIN &&
-        !mts.tile_versions[mts.raster_mode].raster_task_) {
-      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
-      continue;
-    }
-
-    // Insert the tile into a priority set.
-    tiles->InsertTile(tile, mts.bin);
-  }
-}
-
 void TileManager::ManageTiles(const GlobalStateThatImpactsTilePriority& state) {
   TRACE_EVENT0("cc", "TileManager::ManageTiles");
 
   // Update internal state.
-  if (state != global_state_) {
-    global_state_ = state;
-    prioritized_tiles_dirty_ = true;
-  }
+  global_state_ = state;
+
+  // TODO(vmpstr): See if we still need to keep tiles alive when layers release
+  // them.
+  CleanUpReleasedTiles();
 
   // We need to call CheckForCompletedTasks() once in-between each call
   // to ScheduleTasks() to prevent canceled tasks from being scheduled.
@@ -670,11 +414,8 @@ void TileManager::ManageTiles(const GlobalStateThatImpactsTilePriority& state) {
     did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
   }
 
-  UpdatePrioritizedTileSetIfNeeded();
-
   TileVector tiles_that_need_to_be_rasterized;
-  AssignGpuMemoryToTiles(&prioritized_tiles_,
-                         &tiles_that_need_to_be_rasterized);
+  AssignGpuMemoryToTiles(&tiles_that_need_to_be_rasterized);
 
   // Finally, schedule rasterizer tasks.
   ScheduleTasks(tiles_that_need_to_be_rasterized);
@@ -716,8 +457,10 @@ void TileManager::GetMemoryStats(size_t* memory_required_bytes,
                                  size_t* memory_nice_to_have_bytes,
                                  size_t* memory_allocated_bytes,
                                  size_t* memory_used_bytes) const {

[reveman, 2014/06/14 14:53:24]

Let's remove this function completely in a separate patch. Doesn't make sense to
have the tile manager provide these values anymore. I think LTHI is in a much
better position to provide these values. ie. the staging pool resources used
with one-copy rasterizer should probably be included too.

[vmpstr, 2014/06/16 18:18:19]

Sounds good.

-  *memory_required_bytes = memory_required_bytes_;
-  *memory_nice_to_have_bytes = memory_nice_to_have_bytes_;
+  *memory_required_bytes = resource_pool_->total_memory_usage_bytes() +

[vmpstr, 2014/06/13 21:08:38]

ccameron@, can you please take a look to see if this is still needed; if so, is
this acceptable for the memory manager or should this provide some other
information?

+                           bytes_required_but_not_allocated_;
+  *memory_nice_to_have_bytes = resource_pool_->total_memory_usage_bytes() +
+                               bytes_required_but_not_allocated_;
   *memory_allocated_bytes = resource_pool_->total_memory_usage_bytes();
   *memory_used_bytes = resource_pool_->acquired_memory_usage_bytes();
 }
@@ -757,8 +500,67 @@ scoped_ptr<base::Value> TileManager::GetMemoryRequirementsAsValue() const {
   return requirements.PassAs<base::Value>();
 }
 
+bool TileManager::FreeTileResourcesUntilUsageIsWithinBudget(
+    EvictionTileIterator* eviction_iterator,
+    const MemoryBudget& required_budget,
+    MemoryBudget* current_budget,
+    const TilePriority& max_priority,
+    bool evict_unconditionally) {
+  bool evicted_tiles_required_for_activation = false;
+  while (required_budget.Exceeds(*current_budget)) {
+    if (!*eviction_iterator)
+      break;
+
+    Tile* eviction_tile = **eviction_iterator;
+    DCHECK(eviction_tile);
+
+    TilePriority eviction_priority =
+        eviction_tile->priority_for_tree_priority(global_state_.tree_priority);
+
+    if (!evict_unconditionally &&
+        !max_priority.IsHigherPriorityThan(eviction_priority))
+      break;
+
+    size_t eviction_bytes_if_allocated =
+        BytesConsumedIfAllocated(eviction_tile);
+    ManagedTileState& eviction_mts = eviction_tile->managed_state();
+    for (int mode = 0; mode < NUM_RASTER_MODES; ++mode) {
+      if (eviction_mts.tile_versions[mode].resource_) {
+        current_budget->hard_memory_bytes += eviction_bytes_if_allocated;
+        if (eviction_priority.priority_bin != TilePriority::NOW)
+          current_budget->soft_memory_bytes += eviction_bytes_if_allocated;
+        current_budget->resource_count++;
+      }
+    }
+    FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(eviction_tile);
+    ++(*eviction_iterator);
+
+    evicted_tiles_required_for_activation |=
+        eviction_tile->required_for_activation();
+  }
+  return evicted_tiles_required_for_activation;
+}
+
+bool TileManager::TilePriorityViolatesMemoryPolicy(
+    const TilePriority& priority) {
+  switch (global_state_.memory_limit_policy) {
+    case ALLOW_NOTHING:
+      return true;
+    case ALLOW_ABSOLUTE_MINIMUM:
+      return priority.priority_bin > TilePriority::NOW;
+    case ALLOW_PREPAINT_ONLY:
+      return priority.priority_bin > TilePriority::SOON;
+    case ALLOW_ANYTHING:
+      return priority.distance_to_visible ==
+             std::numeric_limits<float>::infinity();
+    case NUM_TILE_MEMORY_LIMIT_POLICIES:

[reveman, 2014/06/14 14:53:24]

please move NOTREACHED below so it fails if some random invalid value has been
written to .memory_limit_policy.

[vmpstr, 2014/06/16 18:18:19]

Done.

+      NOTREACHED();
+      break;
+  }
+  return true;
+}
+
 void TileManager::AssignGpuMemoryToTiles(
-    PrioritizedTileSet* tiles,
     TileVector* tiles_that_need_to_be_rasterized) {
   TRACE_EVENT0("cc", "TileManager::AssignGpuMemoryToTiles");
 
@@ -772,38 +574,47 @@ void TileManager::AssignGpuMemoryToTiles(
   // Now give memory out to the tiles until we're out, and build
   // the needs-to-be-rasterized queue.
   all_tiles_that_need_to_be_rasterized_have_memory_ = true;
-  all_tiles_required_for_activation_have_memory_ = true;
 
+  MemoryBudget budget;
   // Cast to prevent overflow.
-  int64 soft_bytes_available =
-      static_cast<int64>(bytes_releasable_) +
+  budget.soft_memory_bytes =
       static_cast<int64>(global_state_.soft_memory_limit_in_bytes) -
       static_cast<int64>(resource_pool_->acquired_memory_usage_bytes());
-  int64 hard_bytes_available =
-      static_cast<int64>(bytes_releasable_) +
+  budget.hard_memory_bytes =
       static_cast<int64>(global_state_.hard_memory_limit_in_bytes) -
       static_cast<int64>(resource_pool_->acquired_memory_usage_bytes());
-  int resources_available = resources_releasable_ +
-                            global_state_.num_resources_limit -
-                            resource_pool_->acquired_resource_count();
-  size_t soft_bytes_allocatable =
-      std::max(static_cast<int64>(0), soft_bytes_available);
-  size_t hard_bytes_allocatable =
-      std::max(static_cast<int64>(0), hard_bytes_available);
-  size_t resources_allocatable = std::max(0, resources_available);
+  budget.resource_count = global_state_.num_resources_limit -
+                          resource_pool_->acquired_resource_count();
+
+  MemoryBudget initial_budget = budget;
+
+  EvictionTileIterator eviction_it(this, global_state_.tree_priority);
+
+  MemoryBudget required_budget;
+  required_budget.soft_memory_bytes = 0;
+  required_budget.hard_memory_bytes = 0;
+  required_budget.resource_count = 0;
+
+  bool evicted_tiles_required_for_activation =
+      FreeTileResourcesUntilUsageIsWithinBudget(
+          &eviction_it, required_budget, &budget, TilePriority(), true);
 
   size_t bytes_that_exceeded_memory_budget = 0;
-  size_t soft_bytes_left = soft_bytes_allocatable;
-  size_t hard_bytes_left = hard_bytes_allocatable;
 
-  size_t resources_left = resources_allocatable;
   bool oomed_soft = false;
   bool oomed_hard = false;
   bool have_hit_soft_memory = false;  // Soft memory comes after hard.
 
   unsigned schedule_priority = 1u;
-  for (PrioritizedTileSet::Iterator it(tiles, true); it; ++it) {
+  RasterTileIterator it(this, global_state_.tree_priority);
+  for (; it; ++it) {
     Tile* tile = *it;
+    TilePriority priority =
+        tile->priority_for_tree_priority(global_state_.tree_priority);
+
+    if (TilePriorityViolatesMemoryPolicy(priority))
+      break;
+
     ManagedTileState& mts = tile->managed_state();
 
     mts.scheduled_priority = schedule_priority++;
@@ -813,20 +624,13 @@ void TileManager::AssignGpuMemoryToTiles(
     ManagedTileState::TileVersion& tile_version =
         mts.tile_versions[mts.raster_mode];
 
-    // If this tile doesn't need a resource, then nothing to do.
-    if (!tile_version.requires_resource())
+    // If this tile version is ready to draw, then nothing to do.
+    if (tile_version.IsReadyToDraw())
       continue;
 
-    // If the tile is not needed, free it up.
-    if (mts.bin == NEVER_BIN) {
-      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
-      continue;
-    }
-
-    const bool tile_uses_hard_limit = mts.bin <= NOW_BIN;
+    const bool tile_uses_hard_limit =
+        priority.priority_bin == TilePriority::NOW;
     const size_t bytes_if_allocated = BytesConsumedIfAllocated(tile);
-    const size_t tile_bytes_left =
-        (tile_uses_hard_limit) ? hard_bytes_left : soft_bytes_left;
 
     // Hard-limit is reserved for tiles that would cause a calamity
     // if they were to go away, so by definition they are the highest
@@ -834,8 +638,8 @@ void TileManager::AssignGpuMemoryToTiles(
     DCHECK(!(have_hit_soft_memory && tile_uses_hard_limit));
     have_hit_soft_memory |= !tile_uses_hard_limit;
 
-    size_t tile_bytes = 0;
-    size_t tile_resources = 0;
+    int64 tile_bytes = 0;
+    int tile_resources = 0;
 
     // It costs to maintain a resource.
     for (int mode = 0; mode < NUM_RASTER_MODES; ++mode) {
@@ -845,25 +649,30 @@ void TileManager::AssignGpuMemoryToTiles(
       }
     }
 
-    // Allow lower priority tiles with initialized resources to keep
-    // their memory by only assigning memory to new raster tasks if
-    // they can be scheduled.
-    bool reached_scheduled_raster_tasks_limit =
-        tiles_that_need_to_be_rasterized->size() >= kScheduledRasterTasksLimit;
-    if (!reached_scheduled_raster_tasks_limit) {
-      // If we don't have the required version, and it's not in flight
-      // then we'll have to pay to create a new task.
-      if (!tile_version.resource_ && !tile_version.raster_task_) {
-        tile_bytes += bytes_if_allocated;
-        tile_resources++;
-      }
+    // If we don't have the required version, and it's not in flight
+    // then we'll have to pay to create a new task.
+    if (!tile_version.resource_ && !tile_version.raster_task_) {
+      tile_bytes += bytes_if_allocated;
+      tile_resources++;
     }
 
-    // Tile is OOM.
-    if (tile_bytes > tile_bytes_left || tile_resources > resources_left) {
-      bool was_ready_to_draw = tile->IsReadyToDraw();
-
-      FreeResourcesForTile(tile);
+    required_budget.soft_memory_bytes = 0;
+    required_budget.hard_memory_bytes = 0;
+    required_budget.resource_count = tile_resources;
+    if (tile_uses_hard_limit)
+      required_budget.hard_memory_bytes = tile_bytes;
+    else
+      required_budget.soft_memory_bytes = tile_bytes;
+
+    // Handle OOM tiles.
+    evicted_tiles_required_for_activation =
+        FreeTileResourcesUntilUsageIsWithinBudget(
+            &eviction_it, required_budget, &budget, priority, false) ||
+        evicted_tiles_required_for_activation;
+
+    // Tile is still OOM.
+    if (required_budget.Exceeds(budget)) {
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
 
       // This tile was already on screen and now its resources have been
       // released. In order to prevent checkerboarding, set this tile as
@@ -871,19 +680,17 @@ void TileManager::AssignGpuMemoryToTiles(
       if (mts.visible_and_ready_to_draw)
         tile_version.set_rasterize_on_demand();
 
-      if (was_ready_to_draw)
-        client_->NotifyTileStateChanged(tile);
-
       oomed_soft = true;
       if (tile_uses_hard_limit) {
         oomed_hard = true;
         bytes_that_exceeded_memory_budget += tile_bytes;
       }
     } else {
-      resources_left -= tile_resources;
-      hard_bytes_left -= tile_bytes;
-      soft_bytes_left =
-          (soft_bytes_left > tile_bytes) ? soft_bytes_left - tile_bytes : 0;
+      budget.resource_count -= tile_resources;
+      budget.hard_memory_bytes -= tile_bytes;
+      budget.soft_memory_bytes = (budget.soft_memory_bytes > tile_bytes)
+                                     ? budget.soft_memory_bytes - tile_bytes
+                                     : 0;
       if (tile_version.resource_)
         continue;
     }
@@ -899,19 +706,44 @@ void TileManager::AssignGpuMemoryToTiles(
     // 2. Tiles with existing raster task could otherwise incorrectly
     //    be added as they are not affected by |bytes_allocatable|.
     bool can_schedule_tile =
-        !oomed_soft && !reached_scheduled_raster_tasks_limit;
+        !oomed_soft &&
+        tiles_that_need_to_be_rasterized->size() < kScheduledRasterTasksLimit;
 
     if (!can_schedule_tile) {
       all_tiles_that_need_to_be_rasterized_have_memory_ = false;
-      if (tile->required_for_activation())
-        all_tiles_required_for_activation_have_memory_ = false;
-      it.DisablePriorityOrdering();
-      continue;
+      break;
     }
 
     tiles_that_need_to_be_rasterized->push_back(tile);
   }
 
+  // Count up the memory that would be required on top of the allocated memory
+  // in order to initialize all visible tiles.
+  // TODO(vmpstr): Remove this once the memory manager doesn't need required
+  // bytes.
+  bytes_required_but_not_allocated_ = 0;
+  for (; it; ++it) {
+    Tile* tile = *it;
+    TilePriority priority =
+        tile->priority_for_tree_priority(global_state_.tree_priority);
+
+    if (TilePriorityViolatesMemoryPolicy(priority) ||
+        priority.priority_bin != TilePriority::NOW)
+      break;
+
+    ManagedTileState& mts = tile->managed_state();
+    mts.raster_mode = tile->DetermineOverallRasterMode();
+
+    ManagedTileState::TileVersion& tile_version =
+        mts.tile_versions[mts.raster_mode];
+
+    // If this tile version is ready to draw, then nothing to do.
+    if (tile_version.IsReadyToDraw())
+      continue;
+
+    bytes_required_but_not_allocated_ += BytesConsumedIfAllocated(tile);
+  }
+
   // OOM reporting uses hard-limit, soft-OOM is normal depending on limit.
   ever_exceeded_memory_budget_ |= oomed_hard;
   if (ever_exceeded_memory_budget_) {
@@ -926,7 +758,7 @@ void TileManager::AssignGpuMemoryToTiles(
   memory_stats_from_last_assign_.total_budget_in_bytes =
       global_state_.hard_memory_limit_in_bytes;
   memory_stats_from_last_assign_.bytes_allocated =
-      hard_bytes_allocatable - hard_bytes_left;
+      initial_budget.hard_memory_bytes - budget.hard_memory_bytes;
   memory_stats_from_last_assign_.bytes_unreleasable =
       resource_pool_->acquired_memory_usage_bytes() - bytes_releasable_;
   memory_stats_from_last_assign_.bytes_over = bytes_that_exceeded_memory_budget;
@@ -1178,7 +1010,6 @@ scoped_refptr<Tile> TileManager::CreateTile(PicturePileImpl* picture_pile,
 
   tiles_[tile->id()] = tile;
   used_layer_counts_[tile->layer_id()]++;
-  prioritized_tiles_dirty_ = true;
   return tile;
 }
 
@@ -1578,12 +1409,27 @@ bool TileManager::EvictionTileIterator::EvictionOrderComparator::operator()(
       a_tile->priority_for_tree_priority(tree_priority_);
   const TilePriority& b_priority =
       b_tile->priority_for_tree_priority(tree_priority_);
-  bool prioritize_low_res = tree_priority_ != SMOOTHNESS_TAKES_PRIORITY;
+  bool prioritize_low_res = tree_priority_ == SMOOTHNESS_TAKES_PRIORITY;
+
+  // Now we have to return true iff b is lower priority than a.

[vmpstr, 2014/06/13 21:08:38]

This block is parallel to what landed for the raster iterator, let me know if
you prefer this as a separate patch.

[reveman, 2014/06/14 14:53:24]

Yes, I wouldn't mind that.

+
+  // If the bin is the same but the resolution is not, then the order will be
+  // determined by whether we prioritize low res or not.
+  // TODO(vmpstr): Remove this when TilePriority is no longer a member of Tile
+  // class but instead produced by the iterators.
+  if (b_priority.priority_bin == a_priority.priority_bin &&
+      b_priority.resolution != a_priority.resolution) {
+    // Non ideal resolution should be sorted higher than other resolutions.
+    if (a_priority.resolution == NON_IDEAL_RESOLUTION)
+      return false;
+
+    if (b_priority.resolution == NON_IDEAL_RESOLUTION)
+      return true;
+
+    if (prioritize_low_res)
+      return a_priority.resolution == LOW_RESOLUTION;
 
-  if (b_priority.resolution != a_priority.resolution) {
-    return (prioritize_low_res && b_priority.resolution == LOW_RESOLUTION) ||
-           (!prioritize_low_res && b_priority.resolution == HIGH_RESOLUTION) ||
-           (a_priority.resolution == NON_IDEAL_RESOLUTION);
+    return a_priority.resolution == HIGH_RESOLUTION;
   }
   return a_priority.IsHigherPriorityThan(b_priority);
 }