cc: Add temporary CHECKs to debug TileManager crash.

cc/tiles/tile_manager.cc

 // 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.
 
 #include "cc/tiles/tile_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 396 matching lines @@
     delete tile;
   }
   released_tiles_.swap(tiles_to_retain);
 }
 
 void TileManager::DidFinishRunningTileTasksRequiredForActivation() {
   TRACE_EVENT0("cc",
                "TileManager::DidFinishRunningTileTasksRequiredForActivation");
   TRACE_EVENT_ASYNC_STEP_INTO1("cc", "ScheduledTasks", this, "running", "state",
                                ScheduledTasksStateAsValue());
+  // TODO(vmpstr): Temporary check to debug crbug.com/642927.
+  CHECK(tile_task_manager_);
   signals_.ready_to_activate = true;
   signals_check_notifier_.Schedule();
 }
 
 void TileManager::DidFinishRunningTileTasksRequiredForDraw() {
   TRACE_EVENT0("cc", "TileManager::DidFinishRunningTileTasksRequiredForDraw");
   TRACE_EVENT_ASYNC_STEP_INTO1("cc", "ScheduledTasks", this, "running", "state",
                                ScheduledTasksStateAsValue());
+  // TODO(vmpstr): Temporary check to debug crbug.com/642927.
+  CHECK(tile_task_manager_);
   signals_.ready_to_draw = true;
   signals_check_notifier_.Schedule();
 }
 
 void TileManager::DidFinishRunningAllTileTasks() {
   TRACE_EVENT0("cc", "TileManager::DidFinishRunningAllTileTasks");
   TRACE_EVENT_ASYNC_END0("cc", "ScheduledTasks", this);
   DCHECK(resource_pool_);
   DCHECK(tile_task_manager_);
 
   has_scheduled_tile_tasks_ = false;
 
   bool memory_usage_above_limit = resource_pool_->memory_usage_bytes() >
                                   global_state_.soft_memory_limit_in_bytes;
 
   if (all_tiles_that_need_to_be_rasterized_are_scheduled_ &&
       !memory_usage_above_limit) {
     // TODO(ericrk): We should find a better way to safely handle re-entrant
     // notifications than always having to schedule a new task.
     // http://crbug.com/498439
+    // TODO(vmpstr): Temporary check to debug crbug.com/642927.
+    CHECK(tile_task_manager_);
     signals_.all_tile_tasks_completed = true;
     signals_check_notifier_.Schedule();
     return;
   }
 
   more_tiles_need_prepare_check_notifier_.Schedule();
 }
 
 bool TileManager::PrepareTiles(
     const GlobalStateThatImpactsTilePriority& state) {
@@ skipping 687 matching lines @@
     image_manager_.UnrefImages(locked_images_);
     locked_images_.clear();
     locked_image_tasks_.clear();
   }
 
   FreeResourcesForReleasedTiles();
 
   resource_pool_->ReduceResourceUsage();
   image_manager_.ReduceMemoryUsage();
 
+  // TODO(vmpstr): Temporary check to debug crbug.com/642927.
+  CHECK(tile_task_manager_);
   signals_.all_tile_tasks_completed = true;
   signals_check_notifier_.Schedule();
 
   // We don't reserve memory for required-for-activation tiles during
   // accelerated gestures, so we just postpone activation when we don't
   // have these tiles, and activate after the accelerated gesture.
   // Likewise if we don't allow any tiles (as is the case when we're
   // invisible), if we have tiles that aren't ready, then we shouldn't
   // activate as activation can cause checkerboards.
   bool wait_for_all_required_tiles =
@@ skipping 10 matching lines @@
   // even when OOM. Note that we can't reuse the queue we used for
   // AssignGpuMemoryToTiles, since the AssignGpuMemoryToTiles call could have
   // evicted some tiles that would not be picked up by the old raster queue.
   bool need_to_signal_activate = MarkTilesOutOfMemory(client_->BuildRasterQueue(
       global_state_.tree_priority,
       RasterTilePriorityQueue::Type::REQUIRED_FOR_ACTIVATION));
   bool need_to_signal_draw = MarkTilesOutOfMemory(client_->BuildRasterQueue(
       global_state_.tree_priority,
       RasterTilePriorityQueue::Type::REQUIRED_FOR_DRAW));
 
+  // TODO(vmpstr): Temporary check to debug crbug.com/642927.
+  CHECK(tile_task_manager_);
   DCHECK(IsReadyToActivate());
   DCHECK(IsReadyToDraw());
   signals_.ready_to_activate = need_to_signal_activate;
   signals_.ready_to_draw = need_to_signal_draw;
   // TODO(ericrk): Investigate why we need to schedule this (not just call it
   // inline). http://crbug.com/498439
   signals_check_notifier_.Schedule();
 }
 
 bool TileManager::MarkTilesOutOfMemory(
@@ skipping 122 matching lines @@
   all_tile_tasks_completed = false;
   did_notify_all_tile_tasks_completed = false;
 }
 
 TileManager::PrioritizedWorkToSchedule::PrioritizedWorkToSchedule() = default;
 TileManager::PrioritizedWorkToSchedule::PrioritizedWorkToSchedule(
     PrioritizedWorkToSchedule&& other) = default;
 TileManager::PrioritizedWorkToSchedule::~PrioritizedWorkToSchedule() = default;
 
 }  // namespace cc