clean up test importer to use webkit_finder and update tests

Tools/Scripts/webkitpy/w3c/test_importer.py

Index: Tools/Scripts/webkitpy/w3c/test_importer.py
diff --git a/Tools/Scripts/webkitpy/w3c/test_importer.py b/Tools/Scripts/webkitpy/w3c/test_importer.py
index b4ba374aa4fd4eb651b236757c1f58aeb48e8a03..119bd7d92862c1e519ca0a4b3e9ce52fa9cfa628 100644
--- a/Tools/Scripts/webkitpy/w3c/test_importer.py
+++ b/Tools/Scripts/webkitpy/w3c/test_importer.py
@@ -97,6 +97,7 @@ import shutil
 import sys
 
 from webkitpy.common.host import Host
+from webkitpy.common.webkit_finder import WebKitFinder
 from webkitpy.common.system.executive import ScriptError
 from webkitpy.w3c.test_parser import TestParser
 from webkitpy.w3c.test_converter import W3CTestConverter
@@ -172,20 +173,18 @@ class TestImporter(object):
 
         self.filesystem = self.host.filesystem
 
-        self._webkit_root = __file__.split(self.filesystem.sep + 'Tools')[0]
+        webkit_finder = WebKitFinder(self.filesystem)
+        self._webkit_root = webkit_finder.webkit_base()
         self.repo_dir = repo_dir
         subdirs = os.path.dirname(os.path.relpath(source_directory, repo_dir))
 
-        self.destination_directory = os.path.join(self.path_from_webkit_root("LayoutTests"), 'w3c', subdirs)
+        self.destination_directory = webkit_finder.path_from_webkit_base("LayoutTests", 'w3c', *subdirs)
 
         self.changeset = CHANGESET_NOT_AVAILABLE
         self.test_status = TEST_STATUS_UNKNOWN
 
         self.import_list = []
 
-    def path_from_webkit_root(self, *comps):
-        return self.filesystem.abspath(self.filesystem.join(self._webkit_root, *comps))
-
     def do_import(self):
         self.find_importable_tests(self.source_directory)
         self.load_changeset()