Enable Site Isolation for Extensions.

chrome/browser/extensions/extension_apitest.cc

Index: chrome/browser/extensions/extension_apitest.cc
diff --git a/chrome/browser/extensions/extension_apitest.cc b/chrome/browser/extensions/extension_apitest.cc
index 0402aacbd18805ad8fc6a9a0ea053c6b4be31bcd..2f14cddaf51e95edf8023fa37c984a0610dc1635 100644
--- a/chrome/browser/extensions/extension_apitest.cc
+++ b/chrome/browser/extensions/extension_apitest.cc
@@ -156,10 +156,7 @@ void ExtensionApiTest::SetUpInProcessBrowserTestFixture() {
   test_config_->SetString(kTestDataDirectory,
                           net::FilePathToFileURL(test_data_dir_).spec());
   test_config_->SetInteger(kTestWebSocketPort, 0);
-  bool isolate_extensions = base::CommandLine::ForCurrentProcess()->HasSwitch(
-                                switches::kSitePerProcess) ||
-                            base::CommandLine::ForCurrentProcess()->HasSwitch(
-                                extensions::switches::kIsolateExtensions);
+  bool isolate_extensions = true;
   test_config_->SetBoolean(kIsolateExtensions, isolate_extensions);
   extensions::TestGetConfigFunction::set_test_config_state(
       test_config_.get());