Retry flaky failures on SwiftShader *SAN builds.

This should green up the TSAN builder.

Bug: chromium:1275223
Change-Id: Id8dc2e35b739caa6688d13fcabfefb9833940d79
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3804745
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Auto-Submit: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>

infra/specs/angle.json

@@ -2786,6 +2786,7 @@
           "--use-angle=swiftshader",
           "--bot-mode",
           "--batch-timeout=600",
+          "--flaky-retries=2",
           "--xvfb"
         ],
         "merge": {

infra/specs/test_suites.pyl

@@ -760,6 +760,8 @@
           '--use-angle=swiftshader',
           '--bot-mode',
           '--batch-timeout=600',
+          # Mitigate flaky crashes in TSAN. http://crbug.com/1275223
+          '--flaky-retries=2',
         ],
         'linux_args': [
           '--xvfb',

scripts/code_generation_hashes/Test_spec_JSON.json

@@ -1,6 +1,6 @@
 {
   "infra/specs/angle.json":
-    "8a8a7e67195c43799d76cb83951f7d40",
+    "8e4899e836a031dbfe78ec9d9ab2bd5a",
   "infra/specs/generate_test_spec_json.py":
     "be4569626aa91f8872664e2d9cef4ac2",
   "infra/specs/mixins.pyl":
@@ -8,7 +8,7 @@
   "infra/specs/test_suite_exceptions.pyl":
     "a68dc6291f827463cca5fb8101999325",
   "infra/specs/test_suites.pyl":
-    "c7b735f634724c882ecff62423ce59ac",
+    "cccf494cea0c32c395c5df9ad8530575",
   "infra/specs/variants.pyl":
     "8cfcaa99fa07ad2a2d5d14f220fd5037",
   "infra/specs/waterfalls.pyl":