Add //third_party/blink/tools/run_web_tests.*,

which is the new name of run-webkit-tests.
This CL also replaces references to "run-webkit-tests" with
"run_web_tests.py".

* //blink/tools/run_layout_tests.py
 Show a message, and run run_web_tests.py.

* //BUILD.gn
 "webkit_layout_tests" doesn't need //third_party/WebKit/Tools/Scripts
 any longer.

* //testing/buildbot/gn_isolate_map.pyl
 Replace run-webkit-tests with run_web_tests.py.

* //third_party/blink/tools/run_web_tests.{bat,py}
 Added.

* //third_party/WebKit/Tools/Scripts/run-webkit-tests
 Show a message.

* Other files: Really trivial changes. In many files, this CL
  replaces "run-webkit-tests" with "run_web_tests.py" in comments or
  strings.

Note that we decided to rename LayoutTests to web_tests.
https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/KKNbuzj-3HY/H8FWgtKrBgAJ


Bug: 829697
Change-Id: I899457cb3bcdb306aa47843a4c767c5980d9edc0
Reviewed-on: https://chromium-review.googlesource.com/1025543
Commit-Queue: Kent Tamura <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Reviewed-by: Quinten Yearsley <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Cr-Commit-Position: refs/heads/master@{#553452}
diff --git a/docs/testing/writing_layout_tests.md b/docs/testing/writing_layout_tests.md
index 18d58e8..80b2a53 100644
--- a/docs/testing/writing_layout_tests.md
+++ b/docs/testing/writing_layout_tests.md
@@ -271,7 +271,7 @@
 `-expected.txt` file that contains the test's expected output.
 
 The baselines are generated automatically when appropriate by
-`run-webkit-tests`, which is described [here](./layout_tests.md), and by the
+`run_web_tests.py`, which is described [here](./layout_tests.md), and by the
 [rebaselining tools](./layout_test_expectations.md).
 
 Text baselines for `testharness.js` should be avoided, as having a text baseline
@@ -315,7 +315,7 @@
 HTTP tests are those under `LayoutTests/http/tests` (or virtual variants). Use a
 locally running HTTP server (Apache) to run them. Tests are served off of ports
 8000 and 8080 for HTTP, and 8443 for HTTPS. If you run the tests using
-`run-webkit-tests`, the server will be started automatically. To run the server
+`run_web_tests.py`, the server will be started automatically. To run the server
 manually to reproduce or debug a failure:
 
 ```bash