Mostly-boilerplate to add MemoryMapSnapshot

snapshot/mac/process_snapshot_mac.cc

Index: snapshot/mac/process_snapshot_mac.cc
diff --git a/snapshot/mac/process_snapshot_mac.cc b/snapshot/mac/process_snapshot_mac.cc
index 7560317a4cab6fd13908c633594a750811bd85ff..215536cc196d036f6db690ff970d1629dc410549 100644
--- a/snapshot/mac/process_snapshot_mac.cc
+++ b/snapshot/mac/process_snapshot_mac.cc
@@ -186,6 +186,12 @@ const ExceptionSnapshot* ProcessSnapshotMac::Exception() const {
   return exception_.get();
 }
 
+std::vector<const MemoryMapRegionSnapshot*> ProcessSnapshotMac::MemoryMap()
+    const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return std::vector<const MemoryMapRegionSnapshot*>();
+}
+
 std::vector<const MemorySnapshot*> ProcessSnapshotMac::ExtraMemory() const {
   INITIALIZATION_STATE_DCHECK_VALID(initialized_);
   return std::vector<const MemorySnapshot*>();