IVGCVSW-4734 Add an Attribute label guid to the relationship message to reduce traffic

Signed-off-by: Finn Williams <Finn.Williams@arm.com>
Change-Id: Ia55c52c12fe3d30eb47bc42c932a33c620dc9197
diff --git a/src/profiling/LabelsAndEventClasses.cpp b/src/profiling/LabelsAndEventClasses.cpp
index fa89f1c..42b4a9d 100644
--- a/src/profiling/LabelsAndEventClasses.cpp
+++ b/src/profiling/LabelsAndEventClasses.cpp
@@ -14,11 +14,13 @@
 ProfilingGuidGenerator LabelsAndEventClasses::m_GuidGenerator;
 
 // Labels (string value + GUID)
+std::string LabelsAndEventClasses::EMPTY_LABEL("");
 std::string LabelsAndEventClasses::NAME_LABEL("name");
 std::string LabelsAndEventClasses::TYPE_LABEL("type");
 std::string LabelsAndEventClasses::INDEX_LABEL("index");
 std::string LabelsAndEventClasses::BACKENDID_LABEL("backendId");
 
+ProfilingStaticGuid LabelsAndEventClasses::EMPTY_GUID(0);
 ProfilingStaticGuid LabelsAndEventClasses::NAME_GUID(
     m_GuidGenerator.GenerateStaticId(LabelsAndEventClasses::NAME_LABEL));
 ProfilingStaticGuid LabelsAndEventClasses::TYPE_GUID(