cc: Remove cc::Thread and cc::ThreadImpl.

cc/layers/nine_patch_layer_unittest.cc

Index: cc/layers/nine_patch_layer_unittest.cc
diff --git a/cc/layers/nine_patch_layer_unittest.cc b/cc/layers/nine_patch_layer_unittest.cc
index 1221f181cb5baac3b54ace822592258255111ed6..69edc2c8b3df5c8484b32202a31bc5df5a779fa0 100644
--- a/cc/layers/nine_patch_layer_unittest.cc
+++ b/cc/layers/nine_patch_layer_unittest.cc
@@ -4,7 +4,6 @@
 
 #include "cc/layers/nine_patch_layer.h"
 
-#include "cc/base/thread.h"
 #include "cc/debug/overdraw_metrics.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/resources/resource_provider.h"
@@ -32,7 +31,7 @@ class MockLayerTreeHost : public LayerTreeHost {
  public:
   explicit MockLayerTreeHost(LayerTreeHostClient* client)
       : LayerTreeHost(client, LayerTreeSettings()) {
-    Initialize(scoped_ptr<Thread>());
+    Initialize(NULL);
   }
 };