Add a field platform_private_footprint_ to ProcessMemoryTotals.

base/trace_event/process_memory_totals.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_TOTALS_H_
 #define BASE_TRACE_EVENT_PROCESS_MEMORY_TOTALS_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 14 matching lines @@
 
   // Called at trace generation time to populate the TracedValue.
   void AsValueInto(TracedValue* value) const;
 
   // Clears up all the data collected.
   void Clear();
 
   uint64_t resident_set_bytes() const { return resident_set_bytes_; }
   void set_resident_set_bytes(uint64_t value) { resident_set_bytes_ = value; }
 
+  // Platform-specific data that will be used to compute the
+  // PrivateMemoryFootprint.
+  struct PlatformPrivateFootprint {
+    // macOS 10.12+
+    uint64_t phys_footprint_bytes = 0;
+
+    // macOS [all versions]
+    uint64_t internal_bytes = 0;
+    uint64_t compressed_bytes = 0;
+
+    // Linux, Android, ChromeOS
+    // TODO(hjd): https://crbug.com/707019
+    uint64_t rss_anon_bytes = 0;
+    uint64_t vm_swap_bytes = 0;
+
+    // On Windows,
+    //   TBD: https://crbug.com/707022
+    // On iOS,
+    //   TBD: https://crbug.com/714961
+  };
+  PlatformPrivateFootprint& GetPlatformPrivateFootprint() {
+    return platform_private_footprint_;
+  }
+
   uint64_t peak_resident_set_bytes() const { return peak_resident_set_bytes_; }
   void set_peak_resident_set_bytes(uint64_t value) {
     peak_resident_set_bytes_ = value;
   }
 
   // On some platforms (recent linux kernels, see goo.gl/sMvAVz) the peak rss
   // can be reset. When is_peak_rss_resettable == true, the peak refers to
   // peak from the previous measurement. When false, it is the absolute peak
   // since the start of the process.
   bool is_peak_rss_resetable() const { return is_peak_rss_resetable_; }
   void set_is_peak_rss_resetable(bool value) { is_peak_rss_resetable_ = value; }
 
   void SetExtraFieldInBytes(const char* name, uint64_t value);
 
  private:
   uint64_t resident_set_bytes_;
   uint64_t peak_resident_set_bytes_;
   bool is_peak_rss_resetable_;
 
+  // Not emitted in the trace as this is intended to be an intermediary in
+  // computation of private memory footprint.
+  PlatformPrivateFootprint platform_private_footprint_;
+
   // Extra metrics for OS-specific statistics.
   std::map<const char*, uint64_t> extra_fields_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessMemoryTotals);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_TOTALS_H_