Update from https://crrev.com/333737

base/trace_event/process_memory_totals.h

Index: base/trace_event/process_memory_totals.h
diff --git a/base/trace_event/process_memory_totals.h b/base/trace_event/process_memory_totals.h
index 29c94c9aaccb6cc60bcc0d092c4bcbc52d938eff..1bf8bdcd7b49698d12aed051a675dfad12df4a49 100644
--- a/base/trace_event/process_memory_totals.h
+++ b/base/trace_event/process_memory_totals.h
@@ -16,16 +16,33 @@ class TracedValue;
 // Data model for process-wide memory stats.
 class BASE_EXPORT ProcessMemoryTotals {
  public:
-  ProcessMemoryTotals() : resident_set_bytes_(0) {}
+  ProcessMemoryTotals();
 
   // Called at trace generation time to populate the TracedValue.
   void AsValueInto(TracedValue* value) const;
 
+  // Clears up all the data collected.
+  void Clear();
+
   uint64 resident_set_bytes() const { return resident_set_bytes_; }
   void set_resident_set_bytes(uint64 value) { resident_set_bytes_ = value; }
 
+  uint64 peak_resident_set_bytes() const { return peak_resident_set_bytes_; }
+  void set_peak_resident_set_bytes(uint64 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; }
+
  private:
   uint64 resident_set_bytes_;
+  uint64 peak_resident_set_bytes_;
+  bool is_peak_rss_resetable_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessMemoryTotals);
 };