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

base/trace_event/memory_dump_request_args.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TRACE_EVENT_MEMORY_DUMP_REQUEST_ARGS_H_
 #define BASE_TRACE_EVENT_MEMORY_DUMP_REQUEST_ARGS_H_
 
 // This file defines the types and structs used to issue memory dump requests.
 // 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 {
 
 // Captures the reason why a memory dump is being requested. This is to allow
 // selective enabling of dumps, filtering and post-processing. Important: this
 // must be kept consistent with
 // services/resource_coordinator/public/cpp/memory/memory_infra_traits.cc.
 enum class MemoryDumpType {
   PERIODIC_INTERVAL,     // Dumping memory at periodic intervals.
@@ skipping 39 matching lines @@
   MemoryDumpLevelOfDetail level_of_detail;
 };
 
 // Args for ProcessMemoryDump and passed to OnMemoryDump calls for memory dump
 // providers. Dump providers are expected to read the args for creating dumps.
 struct MemoryDumpArgs {
   // Specifies how detailed the dumps should be.
   MemoryDumpLevelOfDetail level_of_detail;
 };
 
+struct MemoryDumpCallbackResult {

[Primiano Tucci (use gerrit), 2017/03/21 15:26:06]

maybe add a comment explaiing what this will be for.
Also add a TODO(hjd) to make it explicit that this is not used yet and will be
used soon.

+  struct OSMemDump {
+    uint32_t pss_kb;
+    uint32_t private_dirty;

[Primiano Tucci (use gerrit), 2017/03/21 15:26:06]

+kb

+  };
+  struct ChromeMemDump {
+    uint32_t malloc_total_kb;
+    uint32_t partition_alloc_total_kb;
+    uint32_t blink_gc_total_kb;
+    uint32_t v8_total_kb;
+  };
+
+  // These are for the current process.
+  OSMemDump os_dump;
+  ChromeMemDump chrome_dump;
+
+  // This is optional and is used only in one case (Linux desktop) by the
+  // browser process, when it needs to communicate the details of the
+  // OSMemDump of other processes.
+  std::map<ProcessId, OSMemDump> os_dump_for_child_processes;

[Primiano Tucci (use gerrit), 2017/03/21 15:26:06]

maybe call this |extra_processes_dump|

base is not really supposed to know about browser/"child" processes (although we
stretched this rule in comments a bit, so it's fine there).
I'd probably make the comment a bit more explicit about the use case thoguh. I'd
say something like:
--
In some cases, os stats can only be dumped from a priviledged process to get
around to sandboxing/selinux restrictions (see crbug.com/461788) 
--

+
+  MemoryDumpCallbackResult();
+  ~MemoryDumpCallbackResult();
+};
+
 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);
 
 BASE_EXPORT MemoryDumpLevelOfDetail
 StringToMemoryDumpLevelOfDetail(const std::string& str);
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_DUMP_REQUEST_ARGS_H_