Reland (2): cc: Make tile manager object persist for the length of LTHI.

cc/tiles/tile_manager.h

 // Copyright 2012 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_TILES_TILE_MANAGER_H_
 #define CC_TILES_TILE_MANAGER_H_
 
 #include <deque>
 #include <queue>
 #include <set>
@@ skipping 88 matching lines @@
     // Adding additional values requires increasing kNumberOfTaskSets in
     // tile_task_runner.h
   };
 
   static_assert(NamedTaskSet::ALL == (kNumberOfTaskSets - 1),
                 "NamedTaskSet::ALL should be equal to kNumberOfTaskSets"
                 "minus 1");
 
   static scoped_ptr<TileManager> Create(TileManagerClient* client,
                                         base::SequencedTaskRunner* task_runner,
-                                        ResourcePool* resource_pool,
-                                        TileTaskRunner* tile_task_runner,
                                         size_t scheduled_raster_task_limit);
   ~TileManager() override;
 
   // Assigns tile memory and schedules work to prepare tiles for drawing.
   // - Runs client_->NotifyReadyToActivate() when all tiles required for
   // activation are prepared, or failed to prepare due to OOM.
   // - Runs client_->NotifyReadyToDraw() when all tiles required draw are
   // prepared, or failed to prepare due to OOM.
-  void PrepareTiles(const GlobalStateThatImpactsTilePriority& state);
+  bool PrepareTiles(const GlobalStateThatImpactsTilePriority& state);
+
+  // Synchronously finish any in progress work, cancel the rest, and clean up as
+  // much resources as possible. Also, prevents any future work until a
+  // SetResources call.
+  void FinishTasksAndCleanUp();
+
+  // Set the new given resource pool and tile task runner.

[enne (OOO), 2015/07/06 18:07:25]

Should you leave a comment here that you need to call FinishTasksAndCleanUp
before calling this a second time? Or should that happen automatically in
SetResources rather than DCHECKing?

[vmpstr, 2015/07/06 18:41:35]

In order to ensure that the caller is aware that FinishTasksAndCleanUp is
happening, I'd prefer to do the comment route instead of an implicit call to it.
Added the comment.

+  void SetResources(ResourcePool* resource_pool,
+                    TileTaskRunner* tile_task_runner);
 
   // This causes any completed raster work to finalize, so that tiles get up to
   // date draw information.
   void Flush();
 
   ScopedTilePtr CreateTile(const gfx::Size& desired_texture_size,
                            const gfx::Rect& content_rect,
                            float contents_scale,
                            int layer_id,
                            int source_frame_number,
@@ skipping 59 matching lines @@
     all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
   }
 
   bool HasScheduledTileTasksForTesting() const {
     return has_scheduled_tile_tasks_;
   }
 
  protected:
   TileManager(TileManagerClient* client,
               const scoped_refptr<base::SequencedTaskRunner>& task_runner,
-              ResourcePool* resource_pool,
-              TileTaskRunner* tile_task_runner,
               size_t scheduled_raster_task_limit);
 
   void FreeResourcesForReleasedTiles();
   void CleanUpReleasedTiles();
 
   friend class Tile;
   // Virtual for testing.
   virtual void Release(Tile* tile);
 
   // Overriden from TileTaskRunnerClient:
@@ skipping 120 matching lines @@
   bool has_scheduled_tile_tasks_;
 
   uint64_t prepare_tiles_count_;
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_TILE_MANAGER_H_