cc: Only make num_threads - 1 SkPicture clones.

cc/output/direct_renderer.h

Index: cc/output/direct_renderer.h
diff --git a/cc/output/direct_renderer.h b/cc/output/direct_renderer.h
index 451c7d712ef84d143b0bee8adcbf4c7d1740e380..46bfb56185fd5234901de01ae749bc11ada093ce 100644
--- a/cc/output/direct_renderer.h
+++ b/cc/output/direct_renderer.h
@@ -12,6 +12,7 @@
 #include "cc/output/renderer.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/scoped_resource.h"
+#include "cc/resources/task_graph_runner.h"
 
 namespace cc {
 
@@ -96,6 +97,8 @@ class CC_EXPORT DirectRenderer : public Renderer {
                       bool allow_partial_swap);
   bool UseRenderPass(DrawingFrame* frame, const RenderPass* render_pass);
 
+  void RunOnDemandRasterTask(internal::Task* on_demand_raster_task);
+
   virtual void BindFramebufferToOutputSurface(DrawingFrame* frame) = 0;
   virtual bool BindFramebufferToTexture(DrawingFrame* frame,
                                         const ScopedResource* resource,
@@ -136,6 +139,8 @@ class CC_EXPORT DirectRenderer : public Renderer {
  private:
   gfx::Vector2d enlarge_pass_texture_amount_;
 
+  internal::NamespaceToken on_demand_task_namespace_;
+
   DISALLOW_COPY_AND_ASSIGN(DirectRenderer);
 };