Bug 1322446: Use namespaces in stylo's bindings. r=heycam

Servo patch: https://github.com/servo/servo/pull/14472

MozReview-Commit-ID: 1YHF10pP19s

--HG--
extra : rebase_source : bfba38429376648ea44504cb23c42b74719021b6

layout/style/nsStyleStruct.h

@@ -3958,7 +3958,7 @@ STATIC_ASSERT_FIELD_OFFSET_MATCHES(nsSize, nsSize_Simple, width);
 STATIC_ASSERT_FIELD_OFFSET_MATCHES(nsSize, nsSize_Simple, height);
 
 /**
- * <div rustbindgen="true" replaces="mozilla_UniquePtr">
+ * <div rustbindgen="true" replaces="mozilla::UniquePtr">
  *
  * TODO(Emilio): This is a workaround and we should be able to get rid of this
  * one.