Blacklist all builders who specify add_tests_as_compile_targets=False.

testing/buildbot/manage.py

Index: testing/buildbot/manage.py
diff --git a/testing/buildbot/manage.py b/testing/buildbot/manage.py
index 7a39176649a0cd2c8a6a8050092f5b1569ba44dc..64d3c957bae2f0424ce0a4b1fac3f123200c505f 100755
--- a/testing/buildbot/manage.py
+++ b/testing/buildbot/manage.py
@@ -42,9 +42,29 @@ SKIP = {
   'Linux GN (dbg)',
   'linux_chromium_gn_rel',
 
-  # Unmaintained builders on chromium.fyi
+  # Clang builders want to build everything, the current hack is to use
+  # add_tests_as_compile_targets=False which interfere with isolated testing.
+  # Blocked by http://crbug.com/503241.
+  'ClangToTLinux tester',
+  'ClangToTLinuxASan tester',
+  'ClangToTMac tester',
   'ClangToTMac',
+  'ClangToTMacASan tester',
   'ClangToTMacASan',
+  'ClangToTWin tester',
+  'ClangToTWin(dbg) tester',
+  'ClangToTWin(dll) tester',
+  'ClangToTWin64 tester',
+  'ClangToTWin64(dbg) tester',
+  'ClangToTWin64(dll) tester',
+  'CrWinClang tester',
+  'CrWinClang(dbg) tester',
+  'CrWinClang(shared) tester',
+  'CrWinClang64 tester',
+  'CrWinClang64(dbg) tester',
+  'CrWinClang64(dll) tester',
+  'CrWinClangLLD tester',
+
 
   # This builder is fine, but win8_chromium_ng uses GN and this configuration,
   # which breaks everything.