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

tools/telemetry/telemetry/core/platform/linux_platform_backend_unittest.py

Index: tools/telemetry/telemetry/core/platform/linux_platform_backend_unittest.py
diff --git a/tools/telemetry/telemetry/core/platform/linux_platform_backend_unittest.py b/tools/telemetry/telemetry/core/platform/linux_platform_backend_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..ca6d15f902c9c4d8bdf444bfed9c8c1551c9bd7d
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/linux_platform_backend_unittest.py
@@ -0,0 +1,72 @@
+# Copyright 2014 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 os
+import unittest
+
+from telemetry import decorators
+from telemetry.core import util
+from telemetry.core.platform import linux_platform_backend
+
+class TestBackend(
+    linux_platform_backend.LinuxPlatformBackend):
+
+  def __init__(self):
+    super(TestBackend, self).__init__()
+    self._mock_files = {}
+
+  def SetMockFile(self, filename, output):
+    self._mock_files[filename] = output
+
+  def _GetFileContents(self, filename):
+    return self._mock_files[filename]
+
+  def StartRawDisplayFrameRateMeasurement(self):
+    raise NotImplementedError()
+
+  def StopRawDisplayFrameRateMeasurement(self):
+    raise NotImplementedError()
+
+  def GetRawDisplayFrameRateMeasurements(self):
+    raise NotImplementedError()
+
+  def IsThermallyThrottled(self):
+    raise NotImplementedError()
+
+  def HasBeenThermallyThrottled(self):
+    raise NotImplementedError()
+
+  def GetSystemCommitCharge(self):
+    raise NotImplementedError()
+
+  def StopVideoCapture(self):
+    raise NotImplementedError()
+
+  def StartVideoCapture(self, min_bitrate_mbps):
+    raise NotImplementedError()
+
+  def GetSystemTotalPhysicalMemory(self):
+    raise NotImplementedError()
+
+
+class LinuxPlatformBackendTest(unittest.TestCase):
+  @decorators.Enabled('linux')
+  def testGetOSVersionNameSaucy(self):
+    backend = TestBackend()
+    path = os.path.join(util.GetUnittestDataDir(), 'ubuntu-saucy-lsb-release')
+    with open(path) as f:
+      backend.SetMockFile('/etc/lsb-release', f.read())
+
+    self.assertEqual(backend.GetOSVersionName(), 'saucy')
+
+  @decorators.Enabled('linux')
+  def testGetOSVersionNameArch(self):
+    backend = TestBackend()
+    path = os.path.join(util.GetUnittestDataDir(), 'arch-lsb-release')
+    with open(path) as f:
+      backend.SetMockFile('/etc/lsb-release', f.read())
+
+    # a distribution may not have a codename or a release number. We just check
+    # that GetOSVersionName doesn't raise an exception
+    backend.GetOSVersionName()