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

cc/playback/display_item_list.cc

Index: cc/playback/display_item_list.cc
diff --git a/cc/playback/display_item_list.cc b/cc/playback/display_item_list.cc
index 91f9cf297a42d79999cb224bcf5799b96607156e..7fb037a7afddea2da02a674b4d92adfdd90f7433 100644
--- a/cc/playback/display_item_list.cc
+++ b/cc/playback/display_item_list.cc
@@ -237,9 +237,9 @@ bool DisplayItemList::ShouldBeAnalyzedForSolidColor() const {
   return ApproximateOpCount() <= kOpCountThatIsOkToAnalyze;
 }
 
-scoped_ptr<base::trace_event::ConvertableToTraceFormat>
+std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 DisplayItemList::AsValue(bool include_items) const {
-  scoped_ptr<base::trace_event::TracedValue> state(
+  std::unique_ptr<base::trace_event::TracedValue> state(
       new base::trace_event::TracedValue());
 
   state->BeginDictionary("params");