Update from https://crrev.com/318214

base/trace_event/process_memory_maps.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_PROCESS_MEMORY_MAPS_H_
+#define BASE_TRACE_EVENT_PROCESS_MEMORY_MAPS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+
+namespace base {
+namespace trace_event {
+
+class TracedValue;
+
+// Data model for process-wide memory stats.
+class BASE_EXPORT ProcessMemoryMaps {
+ public:
+  struct VMRegion {
+    static const uint32 kProtectionFlagsRead;
+    static const uint32 kProtectionFlagsWrite;
+    static const uint32 kProtectionFlagsExec;
+
+    uint64 start_address;
+    uint64 size_in_bytes;
+    uint32 protection_flags;
+    std::string mapped_file;
+    uint64 mapped_file_offset;
+    uint64 byte_stats_resident;
+    uint64 byte_stats_anonymous;
+  };
+
+  ProcessMemoryMaps();
+  ~ProcessMemoryMaps();
+
+  void AddVMRegion(const VMRegion& region) { vm_regions_.push_back(region); }
+  const std::vector<VMRegion>& vm_regions() const { return vm_regions_; }
+
+  // Called at trace generation time to populate the TracedValue.
+  void AsValueInto(TracedValue* value) const;
+
+ private:
+  std::vector<VMRegion> vm_regions_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessMemoryMaps);
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_MAPS_H_