Initialize test configuration to a default value.

content/shell/renderer/layout_test/blink_test_runner.cc

Index: content/shell/renderer/layout_test/blink_test_runner.cc
diff --git a/content/shell/renderer/layout_test/blink_test_runner.cc b/content/shell/renderer/layout_test/blink_test_runner.cc
index b0628dc839c5fd5e52c8b686dfdab5c84fbb5ce4..e3b92cc8d600cb1d0a60780755bf5385d4b4e3a8 100644
--- a/content/shell/renderer/layout_test/blink_test_runner.cc
+++ b/content/shell/renderer/layout_test/blink_test_runner.cc
@@ -252,10 +252,10 @@ WebURL RewriteAbsolutePathInCsswgTest(const std::string& utf8_url) {
 BlinkTestRunner::BlinkTestRunner(RenderView* render_view)
     : RenderViewObserver(render_view),
       RenderViewObserverTracker<BlinkTestRunner>(render_view),
+      test_config_(mojom::ShellTestConfiguration::New()),
       is_main_window_(false),
       focus_on_next_commit_(false),
-      leak_detector_(new LeakDetector(this)) {
-}
+      leak_detector_(new LeakDetector(this)) {}
 
 BlinkTestRunner::~BlinkTestRunner() {
 }