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 dab3f5562823f5eadbdac2e7d7488726dee14f14..adfccebb776f1456b48759e3b6a85149a58d6236 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 +398,20 @@ TileManager::~TileManager() {
   rasterizer_->Shutdown();
   rasterizer_->CheckForCompletedTasks();
 
+  FreeResourcesForReleasedTiles();
+  CleanUpReleasedTiles();
+
+  DCHECK_EQ(0u, tiles_.size());
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
 }
 
 void TileManager::Release(Tile* tile) {
+  // Reset priority as tile is ref-counted and might still be used
+  // even though we no longer hold a reference to it here anymore.

[vmpstr, 2014/07/23 16:10:37]

This comment was meant to be for the picture layer tiling, I think. At this
point it's actually not correct. TileManager::Release means that the tile is
_not_ used anywhere anymore. That being said, I don't mind resetting it here (up
to reveman)

[reveman, 2014/07/23 16:26:54]

Yea, this doesn't make sense here.

[sohanjg, 2014/07/24 11:08:41]

Done.

+  tile->SetPriority(ACTIVE_TREE, TilePriority());
+  tile->SetPriority(PENDING_TREE, TilePriority());

[reveman, 2014/07/23 16:26:54]

Please try to reset these when dropping the ref from the picture layer tiling
instead. And keep the DCHECK you had here before. The above comment makes sense
in that context. I'd like to see what that looks like before we resort to
resetting the priority here.

[sohanjg, 2014/07/24 11:08:41]

Done.

+
   prioritized_tiles_dirty_ = true;
   released_tiles_.push_back(tile);
 }
@@ -418,18 +424,28 @@ bool TileManager::ShouldForceTasksRequiredForActivationToComplete() const {
   return global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 }
 
-void TileManager::CleanUpReleasedTiles() {
+void TileManager::FreeResourcesForReleasedTiles() {
   for (std::vector<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_);
+// TODO(sohanjg): Move it to UpdatePrioritizedTileSetIfNeeded to ensure
+// the prioritized set is rebuild.
+void TileManager::CleanUpReleasedTiles() {
+  std::vector<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());
 
@@ -442,15 +458,15 @@ void TileManager::CleanUpReleasedTiles() {
     }
 
     delete tile;
+    it = released_tiles_.erase(it);
   }
-
-  released_tiles_.clear();
 }
 
 void TileManager::UpdatePrioritizedTileSetIfNeeded() {
   if (!prioritized_tiles_dirty_)
     return;
 
+  FreeResourcesForReleasedTiles();
   CleanUpReleasedTiles();
 
   prioritized_tiles_.Clear();
@@ -484,6 +500,8 @@ void TileManager::DidFinishRunningTasks() {
     return;
   }
 
+  FreeResourcesForReleasedTiles();
+
   resource_pool_->ReduceResourceUsage();
 
   // We don't reserve memory for required-for-activation tiles during
@@ -1071,14 +1089,9 @@ 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_);