Use chromium revision instead of blink svn revision when rebaselining layout tests.

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

 # Copyright (c) 2009, Google Inc. All rights reserved.
 # Copyright (c) 2009 Apple 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
@@ skipping 98 matching lines @@
 
     def _added_files(self):
         self._subclass_must_implement()
 
     def _deleted_files(self):
         self._subclass_must_implement()
 
     def display_name(self):
         self._subclass_must_implement()
 
-    def _head_svn_revision(self):
-        return self.svn_revision(self.checkout_root)
-
-    def svn_revision(self, path):
-        """Returns the latest svn revision found in the checkout."""
+    def chromium_revision(self, path):
+        """Returns the latest chromium revision found in the checkout."""
         self._subclass_must_implement()
 
     def timestamp_of_revision(self, path, revision):
         self._subclass_must_implement()
 
     def blame(self, path):
         self._subclass_must_implement()
 
     def has_working_directory_changes(self):
         self._subclass_must_implement()
 
     #--------------------------------------------------------------------------
     # Subclasses must indicate if they support local commits,
     # but the SCM baseclass will only call local_commits methods when this is true.
     @staticmethod
     def supports_local_commits():
         SCM._subclass_must_implement()
 
     def commit_locally_with_message(self, message, commit_all_working_directory_changes=True):
         _log.error("Your source control manager does not support local commits.")
         sys.exit(1)