Shared Raster Worker Threads

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 fac2fd845ce81db11136a986f0437db89f6e8867..306eebb50413d1109de8bff8bbb2afda42d096b3 100644
--- a/cc/resources/raster_worker_pool.h
+++ b/cc/resources/raster_worker_pool.h
@@ -188,6 +188,11 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
   // Returns the format that needs to be used for raster task resources.
   virtual ResourceFormat GetResourceFormat() const = 0;
 
+  // Sets the number of threads to use for running raster tasks.
+  // Can only be called once prior to GetNumRasterThreads().
+  // Caller is responsible for correct ordering.
+  static void SetNumRasterThreads(int num_threads);
+
   // TODO(vmpstr): Figure out an elegant way to not pass this many parameters.
   static RasterTask CreateRasterTask(
       const Resource* resource,
@@ -218,7 +223,7 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
   typedef base::hash_map<TaskMapKey,
                          scoped_refptr<internal::WorkerPoolTask> > TaskMap;
 
-  RasterWorkerPool(ResourceProvider* resource_provider, size_t num_threads);
+  explicit RasterWorkerPool(ResourceProvider* resource_provider);
 
   virtual void OnRasterTasksFinished() = 0;
   virtual void OnRasterTasksRequiredForActivationFinished() = 0;