Update from https://crrev.com/333737

base/trace_event/process_memory_maps.cc

 // 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.
 
 #include "base/trace_event/process_memory_maps.h"
 
 #include "base/format_macros.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace base {
 namespace trace_event {
 
 // static
 const uint32 ProcessMemoryMaps::VMRegion::kProtectionFlagsRead = 4;
 const uint32 ProcessMemoryMaps::VMRegion::kProtectionFlagsWrite = 2;
 const uint32 ProcessMemoryMaps::VMRegion::kProtectionFlagsExec = 1;
 
+ProcessMemoryMaps::VMRegion::VMRegion()
+    : start_address(0),
+      size_in_bytes(0),
+      protection_flags(0),
+      byte_stats_private_dirty_resident(0),
+      byte_stats_private_clean_resident(0),
+      byte_stats_shared_dirty_resident(0),
+      byte_stats_shared_clean_resident(0),
+      byte_stats_swapped(0),
+      byte_stats_proportional_resident(0) {
+}
+
 ProcessMemoryMaps::ProcessMemoryMaps() {
 }
 
 ProcessMemoryMaps::~ProcessMemoryMaps() {
 }
 
 void ProcessMemoryMaps::AsValueInto(TracedValue* value) const {
   static const char kHexFmt[] = "%" PRIx64;
 
   // Refer to the design doc goo.gl/sxfFY8 for the semantic of these fields.
   value->BeginArray("vm_regions");
   for (const auto& region : vm_regions_) {
     value->BeginDictionary();
 
     value->SetString("sa", StringPrintf(kHexFmt, region.start_address));
     value->SetString("sz", StringPrintf(kHexFmt, region.size_in_bytes));
     value->SetInteger("pf", region.protection_flags);
     value->SetString("mf", region.mapped_file);
 
     value->BeginDictionary("bs");  // byte stats
     value->SetString(
         "pss", StringPrintf(kHexFmt, region.byte_stats_proportional_resident));
-    value->SetString("prv",
-                     StringPrintf(kHexFmt, region.byte_stats_private_resident));
-    value->SetString("shr",
-                     StringPrintf(kHexFmt, region.byte_stats_shared_resident));
+    value->SetString(
+        "pd", StringPrintf(kHexFmt, region.byte_stats_private_dirty_resident));
+    value->SetString(
+        "pc", StringPrintf(kHexFmt, region.byte_stats_private_clean_resident));
+    value->SetString(
+        "sd", StringPrintf(kHexFmt, region.byte_stats_shared_dirty_resident));
+    value->SetString(
+        "sc", StringPrintf(kHexFmt, region.byte_stats_shared_clean_resident));
+    value->SetString("sw", StringPrintf(kHexFmt, region.byte_stats_swapped));
     value->EndDictionary();
 
     value->EndDictionary();
   }
   value->EndArray();
 }
 
+void ProcessMemoryMaps::Clear() {
+  vm_regions_.clear();
+}
+
 }  // namespace trace_event
 }  // namespace base