Set telemetry_unittests to be 100% experimental on 'Win10 Tests x64 (dbg)'

Bug: 870673
Change-Id: I024d5bcad65d4d714c38066c71fcca352d21fda9
Reviewed-on: https://chromium-review.googlesource.com/1163623
Commit-Queue: Ned Nguyen <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Cr-Commit-Position: refs/heads/master@{#580869}
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index 1b591a26..a59b067 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -1144,6 +1144,13 @@
       'Win7 FYI Debug (AMD)',
     ],
   },
+  'telemetry_unittests': {
+    'modifications': {
+      'Win10 Tests x64 (dbg)': {
+        'experiment_percentage': 100,  # crbug.com/870673
+      }
+    }
+  },
   'telemetry_perf_unittests': {
     'modifications': {
       # chromium.android