[tracing] Introduce config to setup memory-infra peak detection

base/trace_event/memory_dump_request_args.h

Index: base/trace_event/memory_dump_request_args.h
diff --git a/base/trace_event/memory_dump_request_args.h b/base/trace_event/memory_dump_request_args.h
index f3ff9d8e3b5f6ef6c14706b5411d96974fab9a4f..8b8337bb152aa1b9c72aa10c74684e8cac4c6717 100644
--- a/base/trace_event/memory_dump_request_args.h
+++ b/base/trace_event/memory_dump_request_args.h
@@ -20,11 +20,10 @@ namespace trace_event {
 // Captures the reason why a memory dump is being requested. This is to allow
 // selective enabling of dumps, filtering and post-processing.
 enum class MemoryDumpType {
-  TASK_BEGIN,         // Dumping memory at the beginning of a message-loop task.
-  TASK_END,           // Dumping memory at the ending of a message-loop task.
-  PERIODIC_INTERVAL,  // Dumping memory at periodic intervals.
+  PERIODIC_INTERVAL,     // Dumping memory at periodic intervals.
   EXPLICITLY_TRIGGERED,  // Non maskable dump request.
-  LAST = EXPLICITLY_TRIGGERED // For IPC macros.
+  PEAK_MEMORY_USAGE,     // Dumping memory at detected peak total memory usage.
+  LAST = PEAK_MEMORY_USAGE  // For IPC macros.
 };
 
 // Tells the MemoryDumpProvider(s) how much detailed their dumps should be.
@@ -72,6 +71,8 @@ using MemoryDumpCallback = Callback<void(uint64_t dump_guid, bool success)>;
 
 BASE_EXPORT const char* MemoryDumpTypeToString(const MemoryDumpType& dump_type);
 
+BASE_EXPORT MemoryDumpType StringToMemoryDumpType(const std::string& str);
+
 BASE_EXPORT const char* MemoryDumpLevelOfDetailToString(
     const MemoryDumpLevelOfDetail& level_of_detail);