lacros: Fix ChromeMetricsServiceClientTest.TestRegisterMetricsServiceProviders

I forgot to update the test expectations when I added
LacrosMetricsProvider back in June. We weren't running lacros unit_tests
in CQ/CI back then, so it got filtered out when the bots were brought up.

Fix the test expectations and remove the filter.

Bug: 1150115
Change-Id: I7e87e109ce94532a6a0bc9cf609126b4e80efd63
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2587259
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Auto-Submit: James Cook <jamescook@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836270}

chrome/browser/metrics/chrome_metrics_service_client_unittest.cc

@@ -180,6 +180,11 @@ TEST_F(ChromeMetricsServiceClientTest, TestRegisterMetricsServiceProviders) {
   expected_providers++;
 #endif  // BUILDFLAG(ENABLE_PLUGINS)
 
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+  // LacrosMetricsProvider.
+  expected_providers++;
+#endif  // BUILDFLAG(IS_CHROMEOS_LACROS)
+
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   // AmbientModeMetricsProvider, AssistantServiceMetricsProvider,
   // CrosHealthdMetricsProvider, ChromeOSMetricsProvider,

testing/buildbot/filters/lacros.unit_tests.filter

 # TODO(crbug.com/1111979) Enable all tests on lacros.
 -ChromeContentBrowserClientTest.UserAgentStringOrdering
--ChromeMetricsServiceClientTest.TestRegisterMetricsServiceProviders
 -NativeDesktopMediaListTest.*
 -PermissionMessageCombinationsUnittest.USBSerialBluetoothCoalescing
 -RelaunchNotificationControllerPlatformImplTest.SynchronousNotification