[tracing] Use EstimateMemoryUsage() in deduplicators.

base/trace_event/heap_profiler_stack_frame_deduplicator.cc

Index: base/trace_event/heap_profiler_stack_frame_deduplicator.cc
diff --git a/base/trace_event/heap_profiler_stack_frame_deduplicator.cc b/base/trace_event/heap_profiler_stack_frame_deduplicator.cc
index 49a235051c0731fd930bd7a897fc793cb867ab40..115e649e331ab319715a95c623c3cbec21034452 100644
--- a/base/trace_event/heap_profiler_stack_frame_deduplicator.cc
+++ b/base/trace_event/heap_profiler_stack_frame_deduplicator.cc
@@ -11,6 +11,7 @@
 #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"
 
@@ -23,6 +24,10 @@ StackFrameDeduplicator::FrameNode::FrameNode(StackFrame frame,
 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() {}
 
@@ -116,19 +121,10 @@ void StackFrameDeduplicator::AppendAsTraceFormat(std::string* out) const {
 
 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,

[Primiano Tucci (use gerrit), 2016/11/22 01:15:13]

the previous code was differenciating between resident and allocated memory,
which is quite easy due to the layout of the heap profiler. Why this is begin
dropped?

-                sizeof(StackFrameDeduplicator) + maps_size + frames_resident);
+                sizeof(StackFrameDeduplicator) + memory_usage);
 }
 
 }  // namespace trace_event