Fix race in SecurityExploitBrowserTest and SiteIsolationStatsGathererBrowserTest

content/browser/security_exploit_browsertest.cc

Index: content/browser/security_exploit_browsertest.cc
diff --git a/content/browser/security_exploit_browsertest.cc b/content/browser/security_exploit_browsertest.cc
index 65e8540980716e7ecba81d4189b5264733aec369..b1da40206821de9e412651cf150597edfbf5ca8f 100644
--- a/content/browser/security_exploit_browsertest.cc
+++ b/content/browser/security_exploit_browsertest.cc
@@ -180,7 +180,11 @@ class SecurityExploitBrowserTest : public ContentBrowserTest {
   SecurityExploitBrowserTest() {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ASSERT_TRUE(embedded_test_server()->Start());
+    // EmbeddedTestServer::InitializeAndListen() initializes its |base_url_|
+    // which is required below. This cannot invoke Start() however as that kicks
+    // off the "EmbeddedTestServer IO Thread" which then races with
+    // initialization in ContentBrowserTest::SetUp(), http://crbug.com/674545.
+    ASSERT_TRUE(embedded_test_server()->InitializeAndListen());
 
     // Add a host resolver rule to map all outgoing requests to the test server.
     // This allows us to use "real" hostnames in URLs, which we can use to
@@ -194,6 +198,10 @@ class SecurityExploitBrowserTest : public ContentBrowserTest {
   }
 
   void SetUpOnMainThread() override {
+    // Complete the manual Start() after ContentBrowserTest's own
+    // initialization, ref. comment on InitializeAndListen() above.
+    embedded_test_server()->StartAcceptingConnections();
+
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&net::URLRequestSlowDownloadJob::AddUrlHandler));