[Telemetry] Consider linux distribution number is 0 when it cannot be parsed

tools/telemetry/telemetry/core/platform/linux_platform_backend.py

 # Copyright 2013 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 logging
 import os
 import subprocess
 import sys
 
 from telemetry import decorators
@@ skipping 26 matching lines @@
   def GetOSName(self):
     return 'linux'
 
   @decorators.Cache
   def GetOSVersionName(self):
     if not os.path.exists('/etc/lsb-release'):
       raise NotImplementedError('Unknown Linux OS version')
 
     codename = None
     version = None
-    with open('/etc/lsb-release') as f:
-      for line in f.readlines():
-        key, _, value = line.partition('=')
-        if key == 'DISTRIB_CODENAME':
-          codename = value.strip()
-        elif key == 'DISTRIB_RELEASE':
+    for line in self._GetFileContents('/etc/lsb-release').splitlines():
+      key, _, value = line.partition('=')
+      if key == 'DISTRIB_CODENAME':
+        codename = value.strip()
+      elif key == 'DISTRIB_RELEASE':
+        try:
           version = float(value)
-        if codename and version:
-          break
+        except ValueError:
+          version = 0
+      if codename and version:
+        break
     return platform_backend.OSVersion(codename, version)
 
   def CanFlushIndividualFilesFromSystemCache(self):
     return True
 
   def FlushEntireSystemCache(self):
     p = subprocess.Popen(['/sbin/sysctl', '-w', 'vm.drop_caches=3'])
     p.wait()
     assert p.returncode == 0, 'Failed to flush system cache'
 
@@ skipping 48 matching lines @@
       cloud_storage.GetIfChanged(bin_path, cloud_storage.INTERNAL_BUCKET)
       os.chmod(bin_path, 0755)
     except cloud_storage.CloudStorageError, e:
       logging.error(str(e))
       if fallback_package:
         logging.error('You may proceed by manually installing %s via:\n'
                       'sudo apt-get install %s' % (bin_name, fallback_package))
       sys.exit(1)
 
     assert self.CanLaunchApplication(bin_name), 'Failed to install ' + bin_name