Revert of Fix pylint warnings in webkitpy/common/.

third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py b/third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py
index 012bcfba22d38227fa562d52aac4e343282338c8..5b77580ff787dd91280a96e15f274a4de09e0a23 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py
@@ -30,6 +30,7 @@ import copy
 import logging
 
 from webkitpy.common.memoized import memoized
+from functools import reduce
 
 _log = logging.getLogger(__name__)
 
@@ -51,8 +52,8 @@ class BaselineOptimizer(object):
     def __init__(self, host, port, port_names, skip_scm_commands):
         self._filesystem = host.filesystem
         self._skip_scm_commands = skip_scm_commands
-        self.files_to_delete = []
-        self.files_to_add = []
+        self._files_to_delete = []
+        self._files_to_add = []
         self._scm = host.scm()
         self._default_port = port
         self._ports = {}
@@ -137,11 +138,11 @@ class BaselineOptimizer(object):
         # have the same baseline, then it can be promoted up to be the LayoutTests baseline.
         # All other baselines can only be removed if they're redundant with a baseline earlier
         # in the fallback order. They can never promoted up.
-        directories_preceding_root = self._directories_immediately_preceding_root(baseline_name)
+        directories_immediately_preceding_root = self._directories_immediately_preceding_root(baseline_name)
 
         shared_result = None
         root_baseline_unused = False
-        for directory in directories_preceding_root:
+        for directory in directories_immediately_preceding_root:
             this_result = new_results_by_directory.get(directory)
 
             # If any of these directories don't have a baseline, there's no optimization we can do.
@@ -163,20 +164,21 @@ class BaselineOptimizer(object):
             return
 
         new_results_by_directory[baseline_root] = shared_result
-        for directory in directories_preceding_root:
+        for directory in directories_immediately_preceding_root:
             del new_results_by_directory[directory]
 
     def _find_optimal_result_placement(self, baseline_name):
         results_by_directory = self.read_results_by_directory(baseline_name)
         results_by_port_name = self._results_by_port_name(results_by_directory, baseline_name)
+        port_names_by_result = _invert_dictionary(results_by_port_name)
 
         new_results_by_directory = self._remove_redundant_results(
-            results_by_directory, results_by_port_name, baseline_name)
+            results_by_directory, results_by_port_name, port_names_by_result, baseline_name)
         self._optimize_result_for_root(new_results_by_directory, baseline_name)
 
         return results_by_directory, new_results_by_directory
 
-    def _remove_redundant_results(self, results_by_directory, results_by_port_name, baseline_name):
+    def _remove_redundant_results(self, results_by_directory, results_by_port_name, port_names_by_result, baseline_name):
         new_results_by_directory = copy.copy(results_by_directory)
         for port_name, port in self._ports.items():
             current_result = results_by_port_name.get(port_name)
@@ -217,7 +219,7 @@ class BaselineOptimizer(object):
             return filename.replace(platform_dir, '').split(self._filesystem.sep)[0]
         return '(generic)'
 
-    def move_baselines(self, baseline_name, results_by_directory, new_results_by_directory):
+    def _move_baselines(self, baseline_name, results_by_directory, new_results_by_directory):
         data_for_result = {}
         for directory, result in results_by_directory.items():
             if not result in data_for_result:
@@ -240,7 +242,7 @@ class BaselineOptimizer(object):
                 for platform_dir in sorted(self._platform(filename) for filename in scm_files):
                     _log.debug("      " + platform_dir)
                 if self._skip_scm_commands:
-                    self.files_to_delete.extend(scm_files)
+                    self._files_to_delete.extend(scm_files)
                 else:
                     self._scm.delete_list(scm_files)
             if fs_files:
@@ -266,8 +268,8 @@ class BaselineOptimizer(object):
                 _log.debug("      " + platform_dir)
             if self._skip_scm_commands:
                 # Have adds win over deletes.
-                self.files_to_delete = list(set(self.files_to_delete) - set(file_names))
-                self.files_to_add.extend(file_names)
+                self._files_to_delete = list(set(self._files_to_delete) - set(file_names))
+                self._files_to_add.extend(file_names)
             else:
                 self._scm.add_list(file_names)
         else:
@@ -305,14 +307,14 @@ class BaselineOptimizer(object):
         _log.debug("    After: ")
         self.write_by_directory(new_results_by_directory, _log.debug, "      ")
 
-        self.move_baselines(baseline_name, results_by_directory, new_results_by_directory)
+        self._move_baselines(baseline_name, results_by_directory, new_results_by_directory)
         return True
 
     def _optimize_virtual_root(self, baseline_name, non_virtual_baseline_name):
-        virtual_root_baseline_path = self._filesystem.join(self._layout_tests_dir, baseline_name)
-        if not self._filesystem.exists(virtual_root_baseline_path):
+        virtual_root_expected_baseline_path = self._filesystem.join(self._layout_tests_dir, baseline_name)
+        if not self._filesystem.exists(virtual_root_expected_baseline_path):
             return
-        root_sha1 = self._filesystem.sha1(virtual_root_baseline_path)
+        root_sha1 = self._filesystem.sha1(virtual_root_expected_baseline_path)
 
         results_by_directory = self.read_results_by_directory(non_virtual_baseline_name)
         # See if all the immediate predecessors of the virtual root have the same expected result.
@@ -326,17 +328,17 @@ class BaselineOptimizer(object):
                 break
 
         _log.debug("Deleting redundant virtual root expected result.")
-        if self._skip_scm_commands and virtual_root_baseline_path in self.files_to_add:
-            self.files_to_add.remove(virtual_root_baseline_path)
-        if self._scm.exists(virtual_root_baseline_path):
-            _log.debug("    Deleting (SCM): " + virtual_root_baseline_path)
+        if self._skip_scm_commands and virtual_root_expected_baseline_path in self._files_to_add:
+            self._files_to_add.remove(virtual_root_expected_baseline_path)
+        if self._scm.exists(virtual_root_expected_baseline_path):
+            _log.debug("    Deleting (SCM): " + virtual_root_expected_baseline_path)
             if self._skip_scm_commands:
-                self.files_to_delete.append(virtual_root_baseline_path)
+                self._files_to_delete.append(virtual_root_expected_baseline_path)
             else:
-                self._scm.delete(virtual_root_baseline_path)
+                self._scm.delete(virtual_root_expected_baseline_path)
         else:
-            _log.debug("    Deleting (file system): " + virtual_root_baseline_path)
-            self._filesystem.remove(virtual_root_baseline_path)
+            _log.debug("    Deleting (file system): " + virtual_root_expected_baseline_path)
+            self._filesystem.remove(virtual_root_expected_baseline_path)
 
     def optimize(self, baseline_name):
         # The virtual fallback path is the same as the non-virtual one tacked on to the bottom of the non-virtual path.
@@ -345,16 +347,16 @@ class BaselineOptimizer(object):
         #
         # So, we can optimize the virtual path, then the virtual root and then the regular path.
 
-        self.files_to_delete = []
-        self.files_to_add = []
+        self._files_to_delete = []
+        self._files_to_add = []
         _log.debug("Optimizing regular fallback path.")
         result = self._optimize_subtree(baseline_name)
         non_virtual_baseline_name = self._virtual_base(baseline_name)
         if not non_virtual_baseline_name:
-            return result, self.files_to_delete, self.files_to_add
+            return result, self._files_to_delete, self._files_to_add
 
         self._optimize_virtual_root(baseline_name, non_virtual_baseline_name)
 
         _log.debug("Optimizing non-virtual fallback path.")
         result |= self._optimize_subtree(non_virtual_baseline_name)
-        return result, self.files_to_delete, self.files_to_add
+        return result, self._files_to_delete, self._files_to_add