memory-infra: Add a struct to carry memory use information

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 90a866fa7a3fbd229b0290cf8053f7fa6861127c..a8b3f423cad37f4aaaac3b9f395e4f20b509a65a 100644
--- a/base/trace_event/memory_dump_request_args.h
+++ b/base/trace_event/memory_dump_request_args.h
@@ -9,10 +9,12 @@
 // These are also used in the IPCs for coordinating inter-process memory dumps.
 
 #include <stdint.h>
+#include <map>
 #include <string>
 
 #include "base/base_export.h"
 #include "base/callback.h"
+#include "base/process/process_handle.h"
 
 namespace base {
 namespace trace_event {
@@ -72,6 +74,33 @@ struct MemoryDumpArgs {
   MemoryDumpLevelOfDetail level_of_detail;
 };
 
+// TODO(hjd): Not used yet, see crbug.com/703184
+// Summarises information about memory use as seen by a single process.
+// This information will eventually be passed to a service to be colated
+// and reported.
+struct MemoryDumpCallbackResult {
+  struct OSMemDump {
+    uint32_t resident_set_kb = 0;
+  };
+  struct ChromeMemDump {
+    uint32_t malloc_total_kb = 0;
+    uint32_t partition_alloc_total_kb = 0;
+    uint32_t blink_gc_total_kb = 0;
+    uint32_t v8_total_kb = 0;
+  };
+
+  // These are for the current process.
+  OSMemDump os_dump;
+  ChromeMemDump chrome_dump;
+
+  // In some cases, OS stats can only be dumped from a privileged process to
+  // get around to sandboxing/selinux restrictions (see crbug.com/461788).
+  std::map<ProcessId, OSMemDump> extra_processes_dump;
+
+  MemoryDumpCallbackResult();
+  ~MemoryDumpCallbackResult();
+};
+
 using MemoryDumpCallback = Callback<void(uint64_t dump_guid, bool success)>;
 
 BASE_EXPORT const char* MemoryDumpTypeToString(const MemoryDumpType& dump_type);