[content shell] only instantiate webkit test runners for layout tests

content/shell/shell_content_renderer_client.cc

Index: content/shell/shell_content_renderer_client.cc
diff --git a/content/shell/shell_content_renderer_client.cc b/content/shell/shell_content_renderer_client.cc
index 5c156183522474fa643abe12cb45e8d9a9b59f5c..3ec1c264a1af5a36bb0e5cad2163580d85dce8b0 100644
--- a/content/shell/shell_content_renderer_client.cc
+++ b/content/shell/shell_content_renderer_client.cc
@@ -58,6 +58,8 @@ void ShellContentRendererClient::RenderThreadStarted() {
 }
 
 void ShellContentRendererClient::RenderViewCreated(RenderView* render_view) {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree))
+    return;
   WebKitTestRunner* test_runner = new WebKitTestRunner(render_view);
   if (!ShellRenderProcessObserver::GetInstance()->test_delegate()) {
     ShellRenderProcessObserver::GetInstance()->SetMainWindow(render_view,