[TREE] Refactor to new logging

src/common/group_data.h

@@ -111,4 +111,4 @@ struct ParallelGroupBuilder {
 };
 }  // namespace common
 }  // namespace xgboost
-#endif  // XGBOOST_UTILS_GROUP_DATA_H_
+#endif  // XGBOOST_COMMON_GROUP_DATA_H_

src/global.cc

@@ -5,6 +5,7 @@
  */
 #include <xgboost/objective.h>
 #include <xgboost/metric.h>
+#include <xgboost/tree_model.h>
 
 namespace dmlc {
 DMLC_REGISTRY_ENABLE(::xgboost::ObjFunctionReg);
@@ -40,5 +41,9 @@ Metric* Metric::Create(const char* name) {
     return (e->body)(buf.substr(pos + 1, buf.length()).c_str());
   }
 }
+
+void test() {
+  RegTree tree;
+}
 }  // namespace xgboost