Fix ChromeOS clang build after original change was reverted.

chrome/browser/automation/testing_automation_provider_chromeos.cc

Index: chrome/browser/automation/testing_automation_provider_chromeos.cc
diff --git a/chrome/browser/automation/testing_automation_provider_chromeos.cc b/chrome/browser/automation/testing_automation_provider_chromeos.cc
index b4d65dcee803537dd22a2c74d62a803a606b3306..b339228e517c516f5d44857fcc5e29f57703518f 100644
--- a/chrome/browser/automation/testing_automation_provider_chromeos.cc
+++ b/chrome/browser/automation/testing_automation_provider_chromeos.cc
@@ -1128,11 +1128,3 @@ void TestingAutomationProvider::PowerChanged(
     const chromeos::PowerSupplyStatus& status) {
   power_status = status;
 }
-
-void TestingAutomationProvider::LockScreen() {
-  // Not used, but defined to make clang happy with the overloaded name.
-}
-
-void TestingAutomationProvider::UnlockScreen() {
-  // Not used, but defined to make clang happy with the overloaded name.
-}