[blinkpy] Add method to retrieve system condition tags in blinkpy

These tags will be used to find active expectations for a test run on
a certain system.

Bug: chromium:986447
Change-Id: Iaa2cea234b80ff010581cd3991dbb015cb8995e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1904270Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Rakib Hasan <rmhasan@google.com>
Cr-Commit-Position: refs/heads/master@{#713707}

third_party/blink/tools/blinkpy/web_tests/port/base.py

@@ -253,6 +253,12 @@ class Port(object):
         return 'Port{name=%s, version=%s, architecture=%s, test_configuration=%s}' % (
             self._name, self._version, self._architecture, self._test_configuration)
 
+    def get_platform_tags(self):
+        """Returns system condition tags that are used to find active expectations
+           for a test run on a specific system"""
+        return frozenset([self._options.configuration.lower(), self._version,
+                          self.port_name, self._architecture])
+
     @memoized
     def _flag_specific_config_name(self):
         """Returns the name of the flag-specific configuration which best matches

third_party/blink/tools/blinkpy/web_tests/port/linux_unittest.py

@@ -72,6 +72,10 @@ class LinuxPortTest(port_testcase.PortTestCase, LoggingTestCase):
         for i, path in enumerate(expected_paths):
             self.assertTrue(port.baseline_search_path()[i].endswith(path))
 
+    def test_get_platform_tags(self):
+        port = self.make_port()
+        self.assertEqual(port.get_platform_tags(), {'linux', 'trusty', 'x86_64', 'release'})
+
     def test_baseline_paths(self):
         self.assert_baseline_paths('linux', 'trusty', 'linux', '/win')
         self.assert_baseline_paths('linux-trusty', None, 'linux', '/win')

third_party/blink/tools/blinkpy/web_tests/port/mac_unittest.py

@@ -46,6 +46,10 @@ class MacPortTest(port_testcase.PortTestCase):
     def test_operating_system(self):
         self.assertEqual('mac', self.make_port().operating_system())
 
+    def test_get_platform_tags(self):
+        port = self.make_port()
+        self.assertEqual(port.get_platform_tags(), {'mac', 'mac10.12', 'x86', 'release'})
+
     def test_driver_name_option(self):
         self.assertTrue(self.make_port()._path_to_driver().endswith('Content Shell'))
         port = self.make_port(options=optparse.Values(dict(driver_name='OtherDriver')))

third_party/blink/tools/blinkpy/web_tests/port/win_unittest.py

@@ -53,6 +53,10 @@ class WinPortTest(port_testcase.PortTestCase):
         port = self.make_port(port_name=port_name, os_version=os_version_string)
         self.assertEqual(expected, port.name())
 
+    def test_get_platform_tags(self):
+        port = self.make_port()
+        self.assertEqual(port.get_platform_tags(), {'win', 'win7', 'x86', 'release'})
+
     def test_versions(self):
         port = self.make_port()
         self.assertIn(port.name(), ('win-win7', 'win-win10'))