cc: Only make num_threads - 1 SkPicture clones.

cc/resources/raster_worker_pool.h

Index: cc/resources/raster_worker_pool.h
diff --git a/cc/resources/raster_worker_pool.h b/cc/resources/raster_worker_pool.h
index 9462a3c0fae2302ca0b373bbc74aed8ef46fdb8f..a8fb2fc05653c784e915704dad69ace422ac4219 100644
--- a/cc/resources/raster_worker_pool.h
+++ b/cc/resources/raster_worker_pool.h
@@ -192,6 +192,13 @@ class CC_EXPORT RasterWorkerPool : public internal::WorkerPoolTaskClient {
 
   static int GetNumRasterThreads();
 
+  static internal::TaskGraphRunner* GetTaskGraphRunner();
+
+  static unsigned kOnDemandRasterTaskPriority;
+  static unsigned kRasterFinishedTaskPriority;
+  static unsigned kRasterRequiredForActivationFinishedTaskPriority;
+  static unsigned kRasterTaskPriorityBase;
+
   // TODO(vmpstr): Figure out an elegant way to not pass this many parameters.
   static RasterTask CreateRasterTask(
       const Resource* resource,
@@ -321,10 +328,6 @@ class CC_EXPORT RasterWorkerPool : public internal::WorkerPoolTaskClient {
       const internal::Task::Vector& decode_tasks,
       unsigned priority);
 
-  static unsigned kRasterFinishedTaskPriority;
-  static unsigned kRasterRequiredForActivationFinishedTaskPriority;
-  static unsigned kRasterTaskPriorityBase;
-
  private:
   void OnRasterFinished(const internal::WorkerPoolTask* source);
   void OnRasterRequiredForActivationFinished(