Fill in PlatformPrivateFootprint on Linux

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 25 matching lines @@
   // 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_;
@@ skipping 25 matching lines @@
   // 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_