Add cross origin to Blink-driven preconnect

chrome/browser/net/predictor_browsertest.cc

Index: chrome/browser/net/predictor_browsertest.cc
diff --git a/chrome/browser/net/predictor_browsertest.cc b/chrome/browser/net/predictor_browsertest.cc
index c4ebc559fd76ea783fa357a164c99dbea33be3f7..0aaa4a3b63af7c5beb2b844c8fea3b86391f27d4 100644
--- a/chrome/browser/net/predictor_browsertest.cc
+++ b/chrome/browser/net/predictor_browsertest.cc
@@ -383,5 +383,30 @@ IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, PreconnectAndUse) {
   EXPECT_EQ(1u, connection_listener_->GetReadSocketCount());
 }
 
+// Tests that preconnect warms up a crossorigin socket connection to a test
+// server, and that that socket is later used when fetching an anonymous
+// resource.
+// Note: This test uses a data URI to serve the preconnect hint, to make sure
+// that the network stack doesn't just re-use its connection to the test server.
+IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, PreconnectAndUseAnonymous) {
+  GURL preconnect_url = embedded_test_server()->base_url();
+  // First navigation to content with a preconnect hint.
+  std::string preconnect_content = "<link rel=\"preconnect\" href=\"" +
+                                   preconnect_url.spec() + "\" crossorigin>";
+  NavigateToDataURLWithContent(preconnect_content);
+  connection_listener_->WaitUntilFirstConnectionAccepted();
+  EXPECT_EQ(1u, connection_listener_->GetAcceptedSocketCount());
+  EXPECT_EQ(0u, connection_listener_->GetReadSocketCount());
+
+  // Second navigation to content with a font.
+  std::string font_content = "<script>var font = new FontFace('FontA', 'url(" +
+                             preconnect_url.spec() +
+                             "test.woff2)');font.load();</script>";
+  NavigateToDataURLWithContent(font_content);
+  connection_listener_->WaitUntilFirstConnectionRead();
+  EXPECT_EQ(1u, connection_listener_->GetAcceptedSocketCount());
+  EXPECT_EQ(1u, connection_listener_->GetReadSocketCount());
+}
+
 }  // namespace chrome_browser_net