Don't allow main world initialization while creating the initial empty document

chrome/browser/extensions/extension_bindings_apitest.cc

Index: chrome/browser/extensions/extension_bindings_apitest.cc
diff --git a/chrome/browser/extensions/extension_bindings_apitest.cc b/chrome/browser/extensions/extension_bindings_apitest.cc
index 81e9b926daef425391532fc3d42752084dc67c58..dcb0fb7fef874fadadc629f82db6a85be86cb17c 100644
--- a/chrome/browser/extensions/extension_bindings_apitest.cc
+++ b/chrome/browser/extensions/extension_bindings_apitest.cc
@@ -157,5 +157,17 @@ IN_PROC_BROWSER_TEST_F(ExtensionBindingsApiTest, HandlerFunctionTypeChecking) {
   EXPECT_EQ("success", result);
 }
 
+// Regression test for crbug.com/340382, which was having extension bindings
+// flakily undefined because the script context was improperly classified.
+// Thanks to jhawkins@ for the only known reliable repro.
+IN_PROC_BROWSER_TEST_F(ExtensionBindingsApiTest,
+                       RegressionTestForUndefinedBindings) {
+  // This is important - likely because the signin page does crazy stuff. This
+  // doesn't repro if we don't navigate to the signin page.
+  ui_test_utils::NavigateToURL(browser(), GURL("chrome://chrome-signin"));
+
+  ASSERT_TRUE(RunPlatformAppTest("bindings/chromei18nrepro")) << message_;
+}
+
 }  // namespace
 }  // namespace extensions