Added unit test for stack traces in telemetry crashes.

tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py

Index: tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py
diff --git a/tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py b/tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py
index 603e769910b1e1e9c481cff88330c6a4017c3449..041de993f34800825391013ba347014e0fc14f96 100644
--- a/tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py
+++ b/tools/telemetry/telemetry/internal/backends/chrome/desktop_browser_backend.py
@@ -34,6 +34,23 @@ def ParseCrashpadDateTime(date_time_str):
   return datetime.datetime.strptime(date_time_str, '%Y-%m-%d %H:%M:%S')
 
 
+def GetSymbolBinary(executable, os_name):
+  # Returns binary file where symbols are located.
+  if os_name == 'mac':
+    version_dir = os.path.join(os.path.dirname(executable),
+                               '..',
+                               'Versions')
+    for version_num in os.listdir(version_dir):
+      framework_file = os.path.join(version_dir,
+                                    version_num,
+                                    'Chromium Framework.framework',
+                                    'Chromium Framework')
+      if os.path.isfile(framework_file):
+        return framework_file
+
+  return executable
+
+
 class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
   """The backend for controlling a locally-executed browser instance, on Linux,
   Mac or Windows.
@@ -453,7 +470,8 @@ class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
       cmd = [
           sys.executable,
           generate_breakpad_symbols_command,
-          '--binary=%s' % self._executable,
+          '--binary=%s' % GetSymbolBinary(self._executable,
+                                          self.browser.platform.GetOSName()),
           '--symbols-dir=%s' % symbols_path,
           '--build-dir=%s' % self._browser_directory,
           ]