Add switch to update-test-expectations to show removed lines in dashboard

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
index 4535316c2a0a2c312697e65dde96a3202ce990a5..9810f24ee3e3528b37e594029e947d3911f013a7 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
@@ -25,8 +25,10 @@ will be removed since there's no Crash results.
 
 import argparse
 import logging
+import webbrowser
 
 from webkitpy.layout_tests.models.test_expectations import TestExpectations
+from webkitpy.tool.commands.flaky_tests import FlakyTests
 
 _log = logging.getLogger(__name__)
 
@@ -34,6 +36,11 @@ _log = logging.getLogger(__name__)
 def main(host, bot_test_expectations_factory, argv):
     parser = argparse.ArgumentParser(epilog=__doc__, formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument('--verbose', '-v', action='store_true', default=False, help='enable more verbose logging')
+    parser.add_argument('--show-results',
+                        '-s',
+                        action='store_true',
+                        default=False,
+                        help='Open results dashboard for all removed lines')
     args = parser.parse_args(argv)
 
     logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO, format="%(levelname)s: %(message)s")
@@ -46,10 +53,14 @@ def main(host, bot_test_expectations_factory, argv):
 
     remove_flakes_o_matic = RemoveFlakesOMatic(host,
                                                port,
-                                               bot_test_expectations_factory)
+                                               bot_test_expectations_factory,
+                                               webbrowser)
 
     test_expectations = remove_flakes_o_matic.get_updated_test_expectations()
 
+    if args.show_results:
+        remove_flakes_o_matic.show_removed_results()
+
     remove_flakes_o_matic.write_test_expectations(test_expectations,
                                                   expectations_file)
     return 0
@@ -57,11 +68,13 @@ def main(host, bot_test_expectations_factory, argv):
 
 class RemoveFlakesOMatic(object):
 
-    def __init__(self, host, port, bot_test_expectations_factory):
+    def __init__(self, host, port, bot_test_expectations_factory, browser):
         self._host = host
         self._port = port
         self._expectations_factory = bot_test_expectations_factory
         self._builder_results_by_path = {}
+        self._browser = browser
+        self._expectations_to_remove_list = None
 
     def _can_delete_line(self, test_expectation_line):
         """Returns whether a given line in the expectations can be removed.
@@ -255,6 +268,25 @@ class RemoveFlakesOMatic(object):
             removed_index -= 1
             expectations.pop(removed_index)
 
+    def _expectations_to_remove(self):
+        """Computes and returns the expectation lines that should be removed.
+
+        returns a list of TestExpectationLines that can be removed from the test expectations
+        file. The result is memoized so that subsequent calls will not recompute the result.
+        """
+        if self._expectations_to_remove_list is not None:
+            return self._expectations_to_remove_list
+
+        self._builder_results_by_path = self._get_builder_results_by_path()
+        self._expectations_to_remove_list = []
+        test_expectations = TestExpectations(self._port, include_overrides=False).expectations()
+
+        for expectation in test_expectations:
+            if self._can_delete_line(expectation):
+                self._expectations_to_remove_list.append(expectation)
+
+        return self._expectations_to_remove_list
+
     def get_updated_test_expectations(self):
         """Filters out passing lines from TestExpectations file.
 
@@ -266,16 +298,8 @@ class RemoveFlakesOMatic(object):
             A TestExpectations object with the passing lines filtered out.
         """
 
-        self._builder_results_by_path = self._get_builder_results_by_path()
-
-        expectations_to_remove = []
         test_expectations = TestExpectations(self._port, include_overrides=False).expectations()
-
-        for expectation in test_expectations:
-            if self._can_delete_line(expectation):
-                expectations_to_remove.append(expectation)
-
-        for expectation in expectations_to_remove:
+        for expectation in self._expectations_to_remove():
             index = test_expectations.index(expectation)
             test_expectations.remove(expectation)
 
@@ -286,6 +310,19 @@ class RemoveFlakesOMatic(object):
 
         return test_expectations
 
+    def show_removed_results(self):
+        """Opens removed lines in the results dashboard.
+
+        Opens the results dashboard in the browser, showing all the tests for lines that the script
+        removed from the TestExpectations file and allowing the user to manually confirm the
+        results.
+        """
+        removed_test_names = ','.join(x.name for x in self._expectations_to_remove())
+        url = FlakyTests.FLAKINESS_DASHBOARD_URL % removed_test_names
+
+        _log.info('Opening results dashboard: ' + url)
+        self._browser.open(url)
+
     def write_test_expectations(self, test_expectations, test_expectations_file):
         """Writes the given TestExpectations object to the filesystem.