Simplify ScopedVector<scoped_ptr<T>> to ScopedVector<T>.

tools/gn/function_toolchain.cc

Index: tools/gn/function_toolchain.cc
diff --git a/tools/gn/function_toolchain.cc b/tools/gn/function_toolchain.cc
index 85163c173a5c0607ce44f2bb323e4e0b86402b85..34145f23508e904aa852802374a2de74674d2cc6 100644
--- a/tools/gn/function_toolchain.cc
+++ b/tools/gn/function_toolchain.cc
@@ -342,7 +342,7 @@ Value RunToolchain(Scope* scope,
     *err = Err(function, "Can't define a toolchain in this context.");
     return Value();
   }
-  collector->push_back(new scoped_ptr<Item>(toolchain.PassAs<Item>()));
+  collector->push_back(toolchain.release());
   return Value();
 }