Update from https://crrev.com/327068

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
new file mode 100644
index 0000000000000000000000000000000000000000..4fb033589bc4567a6d828f5a4b4caef845dd5312
--- /dev/null
+++ b/base/trace_event/memory_dump_request_args.h
@@ -0,0 +1,41 @@
+// 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_H_
+#define BASE_TRACE_EVENT_MEMORY_DUMP_REQUEST_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 "base/base_export.h"
+#include "base/callback.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.
+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.
+  EXPLICITLY_TRIGGERED,  // Non maskable dump request.
+  LAST = EXPLICITLY_TRIGGERED // For IPC macros.
+};
+
+using MemoryDumpCallback = Callback<void(uint64 dump_guid, bool success)>;
+
+struct BASE_EXPORT MemoryDumpRequestArgs {
+  // Globally unique identifier. In multi-process dumps, all processes issue a
+  // local dump with the same guid. This allows the trace importers to
+  // reconstruct the global dump.
+  uint64 dump_guid;
+
+  MemoryDumpType dump_type;
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_MEMORY_DUMP_REQUEST_H_