Add out-of-process memory logging stream parsing.

chrome/profiling/backtrace.cc

+// Copyright 2017 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 "chrome/profiling/backtrace.h"
+
+#include <string.h>
+
+#include <algorithm>
+
+#include "base/hash.h"
+#include "chrome/profiling/backtrace_storage.h"
+#include "chrome/profiling/profiling_globals.h"
+
+namespace profiling {
+
+namespace {
+
+size_t ComputeHash(const std::vector<Address>& addrs) {

[awong, 2017/06/19 23:42:05]

Can you add a TODO here assigned to me to fix this to use a fingerprint capable
hash?

+  if (addrs.empty())
+    return 0;
+  // Assume Address is a POD containing only the address with no padding.
+  return base::Hash(reinterpret_cast<const char*>(&addrs[0]),
+                    addrs.size() * sizeof(Address));
+}
+
+}  // namespace
+
+Backtrace::Backtrace(std::vector<Address>&& a)
+    : addrs_(std::move(a)), fingerprint_(ComputeHash(addrs_)) {}
+
+Backtrace::Backtrace(Backtrace&& other) noexcept = default;
+
+Backtrace::~Backtrace() {}
+
+Backtrace& Backtrace::operator=(Backtrace&& other) = default;
+
+bool Backtrace::operator==(const Backtrace& other) const {
+  if (addrs_.size() != other.addrs_.size())
+    return false;
+  return memcmp(addrs_.data(), other.addrs_.data(),
+                addrs_.size() * sizeof(Address)) == 0;
+}
+
+bool Backtrace::operator!=(const Backtrace& other) const {
+  return !operator==(other);
+}
+
+}  // namespace profiling