Update documents after we introduced Mac.txt
We now have two files listing smoke tests. Default.txt for Fuchsia,
and Mac.txt for Mac10.12, 10.13 and 10.14.
Update the document accordingly.
Bug: 1317393
Change-Id: I5516941f8908a6fe4b2aad671f99db56e9cc79a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3618204
Reviewed-by: Xianzhu Wang
Commit-Queue: Weizhong Xia
Cr-Commit-Position: refs/heads/main@{#998692}
diff --git a/docs/testing/web_tests.md b/docs/testing/web_tests.md
index 010e27f..b489ed9 100644
--- a/docs/testing/web_tests.md
+++ b/docs/testing/web_tests.md
@@ -83,13 +83,21 @@
*** promo
Currently only the tests listed in
-[SmokeTests](../../third_party/blink/web_tests/SmokeTests) are run on the
-Fuchsia bots, since running all web tests takes too long on Fuchshia. Most
-developers focus their Blink testing on Linux. We rely on the fact that the
+[Default.txt](../../third_party/blink/web_tests/SmokeTests/Default.txt) are run
+on the Fuchsia bots, since running all web tests takes too long on Fuchshia.
+Most developers focus their Blink testing on Linux. We rely on the fact that the
Linux and Fuchsia behavior is nearly identical for scenarios outside those
covered by the smoke tests.
***
+*** promo
+Similar to Fuchsia's case, the tests listed in [Mac.txt]
+(../../third_party/blink/web_tests/SmokeTests/Mac.txt)
+are run on older mac version bots. By doing this we reduced the resources needed to run
+the tests. This relies on the fact that the majority of web tests will behavior similarly on
+different mac versions.
+***
+
To run only some of the tests, specify their directories or filenames as
arguments to `run_web_tests.py` relative to the web test directory
(`src/third_party/blink/web_tests`). For example, to run the fast form tests,
