cc: Do not cleanup tiles with raster tasks.

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 bf10d9504150aab4e26657a70055f52fad30f463..cdb95a3961d98870abef0ff969620f1e7fd2403c 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -389,9 +389,6 @@ TileManager::~TileManager() {
   // our memory usage to drop to zero.
   global_state_ = GlobalStateThatImpactsTilePriority();
 
-  CleanUpReleasedTiles();
-  DCHECK_EQ(0u, tiles_.size());
-
   RasterTaskQueue empty;
   rasterizer_->ScheduleTasks(&empty);
   orphan_raster_tasks_.clear();
@@ -401,11 +398,15 @@ TileManager::~TileManager() {
   rasterizer_->Shutdown();
   rasterizer_->CheckForCompletedTasks();
 
+  FreeResourcesForReleasedTiles();

[reveman, 2014/07/31 17:00:33]

I tried to refactor RefCountedManaged but I haven't been able to get a result
that I'm happy with. I think a more significant tile garbage collection
mechanism refactor is needed to do this properly.

Let's just keep released_tiles_ as a std::vector<Tile*> and add a
STLDeleteElements(&released_tiles_) call here for now so you can land this.

[sohanjg, 2014/08/01 07:34:17]

Invoking STLDelete.. will still need the Tile Dtor to be made public, are we ok
with that for now ?
Or we keep Tile as ScopedVector for now (as that will have the same overhead for
public Dtor)?

[reveman, 2014/08/01 11:47:12]

How about just doing prioritized_tiles_.Clear() here and then
CleanUpReleasedTiles()?

[sohanjg, 2014/08/01 12:18:37]

Done.
yea..that shud work.

+
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
 }
 
 void TileManager::Release(Tile* tile) {
+  DCHECK(TilePriority() == tile->combined_priority());
+
   prioritized_tiles_dirty_ = true;
   released_tiles_.push_back(tile);
 }
@@ -418,18 +419,30 @@ bool TileManager::ShouldForceTasksRequiredForActivationToComplete() const {
   return global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 }
 
-void TileManager::CleanUpReleasedTiles() {
-  for (std::vector<Tile*>::iterator it = released_tiles_.begin();
+void TileManager::FreeResourcesForReleasedTiles() {
+  for (ScopedVector<Tile>::iterator it = released_tiles_.begin();
        it != released_tiles_.end();
        ++it) {
     Tile* tile = *it;
-    ManagedTileState& mts = tile->managed_state();
+    FreeResourcesForTile(tile);
+  }
+}
 
-    for (int mode = 0; mode < NUM_RASTER_MODES; ++mode) {
-      FreeResourceForTile(tile, static_cast<RasterMode>(mode));
-      orphan_raster_tasks_.push_back(mts.tile_versions[mode].raster_task_);
+void TileManager::CleanUpReleasedTiles() {
+  // Make sure |prioritized_tiles_| doesn't contain any of the tiles
+  // we're about to delete.
+  DCHECK(prioritized_tiles_.Empty());
+
+  ScopedVector<Tile>::iterator it = released_tiles_.begin();
+  while (it != released_tiles_.end()) {
+    Tile* tile = *it;
+
+    if (tile->HasRasterTask()) {
+      ++it;
+      continue;
     }
 
+    DCHECK(!tile->HasResources());
     DCHECK(tiles_.find(tile->id()) != tiles_.end());
     tiles_.erase(tile->id());
 
@@ -441,19 +454,19 @@ void TileManager::CleanUpReleasedTiles() {
       image_decode_tasks_.erase(tile->layer_id());
     }
 
-    delete tile;
+    it = released_tiles_.erase(it);
   }
-
-  released_tiles_.clear();
 }
 
 void TileManager::UpdatePrioritizedTileSetIfNeeded() {
   if (!prioritized_tiles_dirty_)
     return;
 
+  prioritized_tiles_.Clear();
+
+  FreeResourcesForReleasedTiles();
   CleanUpReleasedTiles();
 
-  prioritized_tiles_.Clear();
   GetTilesWithAssignedBins(&prioritized_tiles_);
   prioritized_tiles_dirty_ = false;
 }
@@ -484,6 +497,8 @@ void TileManager::DidFinishRunningTasks() {
     return;
   }
 
+  FreeResourcesForReleasedTiles();
+
   resource_pool_->ReduceResourceUsage();
 
   // We don't reserve memory for required-for-activation tiles during
@@ -1071,14 +1086,9 @@ void TileManager::OnRasterTaskCompleted(
     RasterMode raster_mode,
     const PicturePileImpl::Analysis& analysis,
     bool was_canceled) {
-  TileMap::iterator it = tiles_.find(tile_id);
-  if (it == tiles_.end()) {
-    ++update_visible_tiles_stats_.canceled_count;
-    resource_pool_->ReleaseResource(resource.Pass());
-    return;
-  }
+  DCHECK(tiles_.find(tile_id) != tiles_.end());
 
-  Tile* tile = it->second;
+  Tile* tile = tiles_[tile_id];
   ManagedTileState& mts = tile->managed_state();
   ManagedTileState::TileVersion& tile_version = mts.tile_versions[raster_mode];
   DCHECK(tile_version.raster_task_);