[tracing] Use EstimateMemoryUsage() in deduplicators.

base/trace_event/heap_profiler_stack_frame_deduplicator.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/heap_profiler_stack_frame_deduplicator.h"
 
 #include <inttypes.h>
 #include <stddef.h>
 
 #include <string>
 #include <utility>
 
 #include "base/strings/stringprintf.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "base/trace_event/trace_event_memory_overhead.h"
 
 namespace base {
 namespace trace_event {
 
 StackFrameDeduplicator::FrameNode::FrameNode(StackFrame frame,
                                              int parent_frame_index)
     : frame(frame), parent_frame_index(parent_frame_index) {}
 StackFrameDeduplicator::FrameNode::FrameNode(const FrameNode& other) = default;
 StackFrameDeduplicator::FrameNode::~FrameNode() {}
 
+size_t StackFrameDeduplicator::FrameNode::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(children);
+}
+
 StackFrameDeduplicator::StackFrameDeduplicator() {}
 StackFrameDeduplicator::~StackFrameDeduplicator() {}
 
 int StackFrameDeduplicator::Insert(const StackFrame* beginFrame,
                                    const StackFrame* endFrame) {
   int frame_index = -1;
   std::map<StackFrame, int>* nodes = &roots_;
 
   // Loop through the frames, early out when a frame is null.
   for (const StackFrame* it = beginFrame; it != endFrame; it++) {
@@ skipping 73 matching lines @@
 
     if (frame_node != it_end)
       out->append(",");
   }
 
   out->append("}");  // End the |stackFrames| dictionary.
 }
 
 void StackFrameDeduplicator::EstimateTraceMemoryOverhead(
     TraceEventMemoryOverhead* overhead) {
-  // The sizes here are only estimates; they fail to take into account the
-  // overhead of the tree nodes for the map, but as an estimate this should be
-  // fine.
-  size_t maps_size = roots_.size() * sizeof(std::pair<StackFrame, int>);
-  size_t frames_allocated = frames_.capacity() * sizeof(FrameNode);
-  size_t frames_resident = frames_.size() * sizeof(FrameNode);
-
-  for (const FrameNode& node : frames_)
-    maps_size += node.children.size() * sizeof(std::pair<StackFrame, int>);
-
+  size_t memory_usage =
+      EstimateMemoryUsage(frames_) + EstimateMemoryUsage(roots_);
   overhead->Add("StackFrameDeduplicator",
-                sizeof(StackFrameDeduplicator) + maps_size + frames_allocated,
-                sizeof(StackFrameDeduplicator) + maps_size + frames_resident);
+                sizeof(StackFrameDeduplicator) + memory_usage);
 }
 
 }  // namespace trace_event
 }  // namespace base