Convert //cc from scoped_ptr to std::unique_ptr.

cc/trees/damage_tracker.h

Index: cc/trees/damage_tracker.h
diff --git a/cc/trees/damage_tracker.h b/cc/trees/damage_tracker.h
index bded662e41dc7a27eadff0cfe6671c52f62c66b1..1de19a3d9661d5441f029bafb539a8485354f350 100644
--- a/cc/trees/damage_tracker.h
+++ b/cc/trees/damage_tracker.h
@@ -5,9 +5,10 @@
 #ifndef CC_TREES_DAMAGE_TRACKER_H_
 #define CC_TREES_DAMAGE_TRACKER_H_
 
+#include <memory>
 #include <vector>
+
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer_collections.h"
 #include "ui/gfx/geometry/rect.h"
@@ -29,7 +30,7 @@ class RenderSurfaceImpl;
 // the screen to save GPU computation and bandwidth.
 class CC_EXPORT DamageTracker {
  public:
-  static scoped_ptr<DamageTracker> Create();
+  static std::unique_ptr<DamageTracker> Create();
   ~DamageTracker();
 
   void DidDrawDamagedArea() { current_damage_rect_ = gfx::Rect(); }