Change Isolate Extensions to be off by default.

chrome/browser/chrome_security_exploit_browsertest.cc

Index: chrome/browser/chrome_security_exploit_browsertest.cc
diff --git a/chrome/browser/chrome_security_exploit_browsertest.cc b/chrome/browser/chrome_security_exploit_browsertest.cc
index c95bb562d6bbe45c7bbdbe6b1d24f62d1ba76987..16a0df3f412eac1596b776e7ea9c43256c3a668c 100644
--- a/chrome/browser/chrome_security_exploit_browsertest.cc
+++ b/chrome/browser/chrome_security_exploit_browsertest.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/singleton_tabs.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/extensions/extension_process_policy.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/common/fileapi/webblob_messages.h"
@@ -71,6 +72,13 @@ IN_PROC_BROWSER_TEST_F(ChromeSecurityExploitBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(ChromeSecurityExploitBrowserTest,
                        CreateBlobInExtensionOrigin) {
+  // This test relies on extensions documents running in extension processes,
+  // which is guaranteed with --isolate-extensions. Without it, the checks are
+  // not enforced and this test will time out waiting for the process to be
+  // killed.
+  if (!extensions::IsIsolateExtensionsEnabled())
+    return;
+
   ui_test_utils::NavigateToURL(
       browser(),
       embedded_test_server()->GetURL("a.root-servers.net", "/title1.html"));