Introduce RawVarData and associated classes for serializing PP_Vars

ppapi/shared_impl/var_tracker.cc

Index: ppapi/shared_impl/var_tracker.cc
diff --git a/ppapi/shared_impl/var_tracker.cc b/ppapi/shared_impl/var_tracker.cc
index 951577cacaab8dd2895a2b322d508e044dc41a77..924b1ec8dbe3b1c17cc7df1733d2d0efdfe69c30 100644
--- a/ppapi/shared_impl/var_tracker.cc
+++ b/ppapi/shared_impl/var_tracker.cc
@@ -174,6 +174,11 @@ int VarTracker::GetTrackedWithNoReferenceCountForObject(
   return found->second.track_with_no_reference_count;
 }
 
+// static
+bool VarTracker::IsVarTypeRefcounted(PP_VarType type) {
+  return type >= PP_VARTYPE_STRING;
+}
+
 VarTracker::VarMap::iterator VarTracker::GetLiveVar(const PP_Var& var) {
   return live_vars_.find(static_cast<int32>(var.value.as_id));
 }
@@ -183,10 +188,6 @@ VarTracker::VarMap::const_iterator VarTracker::GetLiveVar(
   return live_vars_.find(static_cast<int32>(var.value.as_id));
 }
 
-bool VarTracker::IsVarTypeRefcounted(PP_VarType type) const {
-  return type >= PP_VARTYPE_STRING;
-}
-
 PP_Var VarTracker::MakeArrayBufferPPVar(uint32 size_in_bytes) {
   CheckThreadingPreconditions();