Update from https://crrev.com/304121

cc/resources/rasterizer.h

 // Copyright 2014 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_RASTERIZER_H_
 #define CC_RESOURCES_RASTERIZER_H_
 
 #include <bitset>
 #include <vector>
 
@@ skipping 69 matching lines @@
 
  protected:
   RasterTask(const Resource* resource, ImageDecodeTask::Vector* dependencies);
   ~RasterTask() override;
 
  private:
   const Resource* resource_;
   ImageDecodeTask::Vector dependencies_;
 };
 
-static const size_t kNumberOfTaskSets = 2;
+// kNumberOfTaskSets must be greater or equal to the number of values in
+// TileManager::NamedTaskSet.
+// TODO(reveman): Use template specialization to make it easy for client code to
+// check at compile time that the number of supported task sets is correct.
+static const size_t kNumberOfTaskSets = 3;
 typedef size_t TaskSet;
 typedef std::bitset<kNumberOfTaskSets> TaskSetCollection;
 
 class CC_EXPORT RasterizerClient {
  public:
   virtual void DidFinishRunningTasks(TaskSet task_set) = 0;
   virtual TaskSetCollection TasksThatShouldBeForcedToComplete() const = 0;
 
  protected:
   virtual ~RasterizerClient() {}
@@ skipping 54 matching lines @@
   // Check for completed tasks and dispatch reply callbacks.
   virtual void CheckForCompletedTasks() = 0;
 
  protected:
   virtual ~Rasterizer() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RASTERIZER_H_