Blink was forked from WebKit in 2013; as of Oct, the Blink codebase in Chromium is in a state where sometimes the name "Blink" is used, and sometimes "WebKit" is used, for legacy reasons.

In general, renaming is hard because:
 (1) names have to be changed everywhere at once, often in multiple repositories.
 (2) Renames often break things unpredictably.

And there are so many names to change that it's very unrealistic to rename many things within a short time frame.

The main benefit of renaming is to reduce confusion. Some things which I think could theoretically be renamed in Tools/Scripts are:

 - Directory names webkitpy, webkitruby
 - Script names run-webkit-tests, webkit-patch, check-webkit-style, debug-webkit-tests
 - Class names TestWebKitPort, WebKitFinder, WebKitPatch...
 - Method names in webkitpy/style: check_webkit_style_parser, check_webkit_style_configuration...
 - Methods in webkitpy/w3c/test_converter.py: convert_for_webkit, path_from_webkit_root...
 - Methods in WebKitFinder and others: webkit_base, path_from_webkit_base

And in our CI system:

 - Master name "chromium.webkit", and builder names under that master
 - Step names webkit_tests, webkit_unit_tests, archive_webkit_tests_results

Not to mention the thousands of occurrences of "webkit" in the blink Source directory, including prefixed CSS properties.