Enable CrOSEnableUSMUserService by default.

Leave the flag in place so we can revert the state in case we have any blockers.

R=escordeiro@chromium.org, xiyuan@chromium.org

Bug: 848827
Change-Id: I448a6e695b9e01ba232ee832e239074a0bd397b6
Reviewed-on: https://chromium-review.googlesource.com/1089134Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: B. Menegola <menegola@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564976}

chrome/common/chrome_features.cc

@@ -637,8 +637,8 @@ const base::Feature kTPMFirmwareUpdate{"TPMFirmwareUpdate",
 
 // Enables or disables "usm" service in the list of user services returned by
 // userInfo Gaia message.
-const base::Feature kCrOSEnableUSMUserService{
-    "CrOSEnableUSMUserService", base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kCrOSEnableUSMUserService{"CrOSEnableUSMUserService",
+                                              base::FEATURE_ENABLED_BY_DEFAULT};
 
 #endif  // defined(OS_CHROMEOS)