Add docstring for AbstractParallelRebaselineCommand._rebaseline.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline.py

 # Copyright (c) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 476 matching lines @@
                 _log.error(line)
 
         files_to_add, files_to_delete, lines_to_remove = self._serial_commands(command_results)
         if files_to_delete:
             self._tool.scm().delete_list(files_to_delete)
         if files_to_add:
             self._tool.scm().add_list(files_to_add)
         return lines_to_remove
 
     def _rebaseline(self, options, test_prefix_list):
+        """Downloads new baselines in parallel, then updates expectations files
+        and optimizes baselines.
+
+        Args:
+            options: An object with the options passed to the current command.
+            test_prefix_list: A map of test names to builder names to baseline
+                suffixes to rebaseline. For example:
+                {
+                    "some/test.html": {"builder-1": ["txt"], "builder-2": ["txt"]},
+                    "some/other.html": {"builder-1": ["txt"]}
+                }
+                This would mean that new text baselines should be downloaded for
+                "some/test.html" on both builder-1 and builder-2, and new text
+                baselines should be downloaded for "some/other.html" but only
+                from builder-1.
+        """
         for test, builders_to_check in sorted(test_prefix_list.items()):
             _log.info("Rebaselining %s" % test)
             for builder, suffixes in sorted(builders_to_check.items()):
                 _log.debug("  %s: %s" % (builder, ",".join(suffixes)))
 
         copy_baseline_commands, rebaseline_commands, extra_lines_to_remove = self._rebaseline_commands(test_prefix_list, options)
         lines_to_remove = {}
 
         self._run_in_parallel_and_update_scm(copy_baseline_commands)
         lines_to_remove = self._run_in_parallel_and_update_scm(rebaseline_commands)
@@ skipping 50 matching lines @@
     def _tests_to_rebaseline(self, port):
         tests_to_rebaseline = {}
         for path, value in port.expectations_dict().items():
             expectations = TestExpectations(port, include_overrides=False, expectations_dict={path: value})
             for test in expectations.get_rebaselining_failures():
                 suffixes = TestExpectations.suffixes_for_expectations(expectations.get_expectations(test))
                 tests_to_rebaseline[test] = suffixes or BASELINE_SUFFIX_LIST
         return tests_to_rebaseline
 
     def _add_tests_to_rebaseline_for_port(self, port_name):
+        """Adds tests to self._test_prefix_list for the given port."""

[wkorman, 2016/06/30 19:17:12]

Which tests does it add?

[qyearsley, 2016/06/30 21:20:39]

I believe it's tests that appear in the TestExpectations file, in this case.

But I'm not sure, and the main point of this CL was supposed to just be adding a
docstring for _rebaseline, so I'd like to remove this line from this CL.

         builder_name = self._tool.builders.builder_name_for_port_name(port_name)
         if not builder_name:
             return
         tests = self._tests_to_rebaseline(self._tool.port_factory.get(port_name)).items()
 
         if tests:
             _log.info("Retrieving results for %s from %s." % (port_name, builder_name))
 
         for test_name, suffixes in tests:
             _log.info("    %s (%s)" % (test_name, ','.join(suffixes)))
@@ skipping 324 matching lines @@
                     issue_already_closed = tool.executive.run_command(
                         ['git', 'config', 'branch.%s.rietveldissue' % rebaseline_branch_name],
                         return_exit_code=True)
                     if not issue_already_closed:
                         self._run_git_cl_command(options, ['set_close'])
 
                 tool.scm().ensure_cleanly_tracking_remote_master()
                 if old_branch_name_or_ref:
                     tool.scm().checkout_branch(old_branch_name_or_ref)
                 tool.scm().delete_branch(rebaseline_branch_name)