Replace DumpBacktrace with Chromium's StackTrace implementation.

src/base/debug/stack_trace.cc

+// Copyright 2016 the V8 project 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 "src/base/debug/stack_trace.h"
+
+#include <string.h>
+
+#include <algorithm>
+#include <sstream>
+
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+namespace debug {
+
+StackTrace::StackTrace(const void* const* trace, size_t count) {
+  count = std::min(count, arraysize(trace_));
+  if (count) memcpy(trace_, trace, count * sizeof(trace_[0]));
+  count_ = count;
+}
+
+StackTrace::~StackTrace() {}
+
+const void* const* StackTrace::Addresses(size_t* count) const {
+  *count = count_;
+  if (count_) return trace_;
+  return NULL;
+}
+
+std::string StackTrace::ToString() const {
+  std::stringstream stream;
+  OutputToStream(&stream);
+  return stream.str();
+}
+
+}  // namespace debug
+}  // namespace base
+}  // namespace v8