Store classloader information in heap dumps.

Bug: 170742283
Change-Id: I0b5b8934187b0e7437a8cca75a36cbc4edd4ba8f
diff --git a/perfetto_hprof/perfetto_hprof.cc b/perfetto_hprof/perfetto_hprof.cc
index 26ceb55..fcaa8e6 100644
--- a/perfetto_hprof/perfetto_hprof.cc
+++ b/perfetto_hprof/perfetto_hprof.cc
@@ -685,6 +685,7 @@
                           klass->GetLocation()));
                     type_proto->set_object_size(klass->GetObjectSize());
                     type_proto->set_kind(ProtoClassKind(klass->GetClassFlags()));
+                    type_proto->set_classloader_id(GetObjectId(klass->GetClassLoader().Ptr()));
                     if (klass->GetSuperClass().Ptr()) {
                       type_proto->set_superclass_id(
                         FindOrAppend(&interned_classes,