unit_tests: re-enable previously flaky extensionservicesync test

crrev.com/c/2795519, which landed after this test was disabled,
should fix this flakiness.

Bug: 1185036
Change-Id: I441ff52c8de48776522914e2f7bace3502a6d478
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2851232
Reviewed-by: David Bertoni <[email protected]>
Commit-Queue: David Bienvenu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#876326}
diff --git a/chrome/browser/extensions/extension_service_sync_unittest.cc b/chrome/browser/extensions/extension_service_sync_unittest.cc
index bff5a5a..cfb3c0ee 100644
--- a/chrome/browser/extensions/extension_service_sync_unittest.cc
+++ b/chrome/browser/extensions/extension_service_sync_unittest.cc
@@ -1578,9 +1578,8 @@
   PackCRXAndUpdateExtension(id, path, pem_path, ENABLED);
 }
 
-// Flaky on a few platforms.
 TEST_F(ExtensionServiceSyncCustomGalleryTest,
-       DISABLED_ProcessSyncDataPermissionApproval) {
+       ProcessSyncDataPermissionApproval) {
   InitializeEmptyExtensionService();
   extension_sync_service()->MergeDataAndStartSyncing(
       syncer::EXTENSIONS, syncer::SyncDataList(),