CC/GPU: Add a soft limit to the compositor.

cc/resources/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_RESOURCES_TILE_MANAGER_H_
 #define CC_RESOURCES_TILE_MANAGER_H_
 
 #include <queue>
 #include <set>
 #include <vector>
@@ skipping 88 matching lines @@
       bytes_releasable_ += BytesConsumedIfAllocated(tiles[i]);
       ++resources_releasable_;
     }
   }
   RasterWorkerPool* RasterWorkerPoolForTesting() {
     return raster_worker_pool_.get();
   }
 
   void SetGlobalStateForTesting(
       const GlobalStateThatImpactsTilePriority& state) {
+    // Soft limit is used for resource pool such that
+    // memory returns to soft limit after going over.
     if (state != global_state_) {
       global_state_ = state;
       prioritized_tiles_dirty_ = true;
       resource_pool_->SetResourceUsageLimits(
-          global_state_.memory_limit_in_bytes,
+          global_state_.soft_memory_limit_in_bytes,
           global_state_.unused_memory_limit_in_bytes,
           global_state_.num_resources_limit);
     }
   }
 
  protected:
   TileManager(TileManagerClient* client,
               ResourceProvider* resource_provider,
               scoped_ptr<RasterWorkerPool> raster_worker_pool,
               size_t max_raster_usage_bytes,
@@ skipping 94 matching lines @@
 
   // Queue used when scheduling raster tasks.
   RasterWorkerPool::RasterTask::Queue raster_tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILE_MANAGER_H_