Reland "Add libfuzzer_tests to chromium.fyi Clang ToT testers (w/ and w/o ASan) on Linux."

Bug: 764514

Original CL: https://chromium-review.googlesource.com/679619

R=dpranke@chromium.org

Change-Id: I412ac11cbe2c73de9e7b724e2689a97144aad47e
Reviewed-on: https://chromium-review.googlesource.com/688029Reviewed-by: Oliver Chang <ochang@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Max Moroz <mmoroz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505167}

testing/buildbot/chromium.fyi.json

@@ -3487,6 +3487,12 @@
         },
         "test": "jingle_unittests"
       },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "libfuzzer_tests"
+      },
       {
         "swarming": {
           "can_use_on_swarming_builders": true
@@ -3816,6 +3822,12 @@
         },
         "test": "jingle_unittests"
       },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "libfuzzer_tests"
+      },
       {
         "swarming": {
           "can_use_on_swarming_builders": true

testing/buildbot/gn_isolate_map.pyl

@@ -666,6 +666,10 @@
     "label": "//components/leveldb:leveldb_service_unittests",
     "type": "console_test_launcher",
   },
+  "libfuzzer_tests": {
+    "label": "//testing/libfuzzer/tests:libfuzzer_tests",
+    "type": "console_test_launcher",
+  },
   "libjingle_xmpp_unittests": {
     "label": "//third_party/libjingle_xmpp:libjingle_xmpp_unittests",
     "type": "console_test_launcher",