html_viewer: Make sure window.internals is set-up correctly in layout-tests.

components/html_viewer/web_test_delegate_impl.cc

Index: components/html_viewer/web_test_delegate_impl.cc
diff --git a/components/html_viewer/web_test_delegate_impl.cc b/components/html_viewer/web_test_delegate_impl.cc
index 12474ec54769aed5157be30984296c6276a5bbd0..5385a660b454a48cbf051db0a7c590c8bca9647a 100644
--- a/components/html_viewer/web_test_delegate_impl.cc
+++ b/components/html_viewer/web_test_delegate_impl.cc
@@ -228,7 +228,8 @@ void WebTestDelegateImpl::SetLocale(const std::string& locale) {
 
 void WebTestDelegateImpl::TestFinished() {
   test_interfaces_->SetTestIsRunning(false);
-  fprintf(stderr, "%s", proxy_->CaptureTree(false, false).c_str());
+  fprintf(stderr, "%s", proxy_ ? proxy_->CaptureTree(false, false).c_str()
+                               : dump_tree_.c_str());
 }
 
 void WebTestDelegateImpl::CloseRemainingWindows() {
@@ -324,4 +325,11 @@ blink::WebPlugin* WebTestDelegateImpl::CreatePluginPlaceholder(
   return nullptr;
 }
 
+void WebTestDelegateImpl::OnWebTestProxyBaseDestroy(
+    test_runner::WebTestProxyBase* base) {
+  DCHECK_EQ(proxy_, base);
+  dump_tree_ = proxy_->CaptureTree(false, false);
+  proxy_ = nullptr;
+}
+
 }  // namespace html_viewer