Add a pref checkbox to enable/disable screen lock for ChromeOs.

chrome/browser/chromeos/cros/cros_mock.cc

Index: chrome/browser/chromeos/cros/cros_mock.cc
diff --git a/chrome/browser/chromeos/cros/cros_mock.cc b/chrome/browser/chromeos/cros/cros_mock.cc
index 58e4720e197d221aadb487b01abdc3a1d2a8e7e5..168bf037e91ef757672310edd98253297e638f83 100644
--- a/chrome/browser/chromeos/cros/cros_mock.cc
+++ b/chrome/browser/chromeos/cros/cros_mock.cc
@@ -188,6 +188,7 @@ void CrosMock::SetStatusAreaMocksExpectations() {
   SetInputMethodLibraryStatusAreaExpectations();
   SetNetworkLibraryStatusAreaExpectations();
   SetPowerLibraryStatusAreaExpectations();
+  SetPowerLibraryExpectations();
   SetTouchpadLibraryExpectations();
   SetSystemLibraryStatusAreaExpectations();
 }
@@ -336,6 +337,13 @@ void CrosMock::SetPowerLibraryStatusAreaExpectations() {
       .RetiresOnSaturation();
 }
 
+void CrosMock::SetPowerLibraryExpectations() {
+  // EnableScreenLock is currently bounded with a prefs value and thus is
+  // always called when loading
+  EXPECT_CALL(*mock_power_library_, EnableScreenLock(_))
+      .Times(AnyNumber());
+}
+
 void CrosMock::SetSpeechSynthesisLibraryExpectations() {
   EXPECT_CALL(*mock_speech_synthesis_library_, Speak(_))
       .Times(1)