[tracing] Reland of Throttle rate of heavy dumps and support to request light/heavy dumps

base/trace_event/memory_dump_request_args.cc

Index: base/trace_event/memory_dump_request_args.cc
diff --git a/base/trace_event/memory_dump_request_args.cc b/base/trace_event/memory_dump_request_args.cc
index a24bc72671d7cce8900bef86626201c7e0f2b9d6..eca98cfb96d4eea60da14be24757f80059b8a493 100644
--- a/base/trace_event/memory_dump_request_args.cc
+++ b/base/trace_event/memory_dump_request_args.cc
@@ -19,8 +19,6 @@ const char* MemoryDumpTypeToString(
       return "TASK_END";
     case MemoryDumpType::PERIODIC_INTERVAL:
       return "PERIODIC_INTERVAL";
-    case MemoryDumpType::PERIODIC_INTERVAL_WITH_MMAPS:
-      return "PERIODIC_INTERVAL_WITH_MMAPS";
     case MemoryDumpType::EXPLICITLY_TRIGGERED:
       return "EXPLICITLY_TRIGGERED";
   }