Ensure previous test preference overrides are reset between tests

content/shell/browser/layout_test/blink_test_controller.cc

Index: content/shell/browser/layout_test/blink_test_controller.cc
diff --git a/content/shell/browser/layout_test/blink_test_controller.cc b/content/shell/browser/layout_test/blink_test_controller.cc
index 4e6a1ede9a1c663d8708e5f09251d95a3ebad156..5b9d1827b01c0545368c4da9f9c521e23baae861 100644
--- a/content/shell/browser/layout_test/blink_test_controller.cc
+++ b/content/shell/browser/layout_test/blink_test_controller.cc
@@ -315,7 +315,6 @@ bool BlinkTestController::PrepareForLayoutTest(
     // Compositing tests override the default preferences (see
     // BlinkTestController::OverrideWebkitPrefs) so we force them to be
     // calculated again to ensure is_compositing_test_ changes are picked up.
-    default_prefs_ = render_view_host->GetWebkitPreferences();
     OverrideWebkitPrefs(&default_prefs_);
 
     render_view_host->UpdateWebkitPreferences(default_prefs_);