Update symbolize_trace to work on macOS.

tracing/bin/symbolize_trace_atos_regex.py

+# 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.
+
+import re
+
+
+class AtosRegexMatcher(object):
+  def __init__(self):
+    """
+    Atos output has two useful forms:
+      1. <name> (in <library name>) (<filename>:<linenumber>)
+      2. <name> (in <library name>) + <symbol offset>
+    And two less useful forms:
+      3. <address>
+      4. <address> (in <library name>)
+    e.g.
+      1. -[SKTGraphicView drawRect:] (in Sketch) (SKTGraphicView.m:445)
+      2. malloc (in libsystem_malloc.dylib) + 42
+      3. 0x4a12
+      4. 0x00000d9a (in Chromium)
+
+    We don't bother checking for the latter two, and just return the full
+    output.
+    """
+    self._regex1 = re.compile(r"(.*) \(in (.+)\) \((.+):(\d+)\)")
+    self._regex2 = re.compile(r"(.*) \(in (.+)\) \+ (\d+)")
+
+  def Match(self, text):
+    result = self._regex1.match(text)
+    if result:
+      return result.group(1)
+    result = self._regex2.match(text)
+    if result:
+      return result.group(1)
+    return text