Add a Subzero variant of Chrome PNaCl error handling test.

chrome/test/nacl/nacl_browsertest.cc

Index: chrome/test/nacl/nacl_browsertest.cc
diff --git a/chrome/test/nacl/nacl_browsertest.cc b/chrome/test/nacl/nacl_browsertest.cc
index 35c43de63e81116328fca73982d4c8820b60a94b..5ce68d8c0e6cf0b15a3fe07d564cad6bfbd9b7b6 100644
--- a/chrome/test/nacl/nacl_browsertest.cc
+++ b/chrome/test/nacl/nacl_browsertest.cc
@@ -381,13 +381,20 @@ IN_PROC_BROWSER_TEST_F(NaClBrowserTestPnacl,
   RunNaClIntegrationTest(FILE_PATH_LITERAL("pnacl_error_handling.html"));
 }
 
+// Test Subzero. Subzero is triggered by the O0 option so reuse
+// test harnesses that use "optlevel": 0.
+IN_PROC_BROWSER_TEST_F(NaClBrowserTestPnaclSubzero,
+                       MAYBE_PNACL(PnaclErrorHandling)) {
+  RunNaClIntegrationTest(FILE_PATH_LITERAL("pnacl_error_handling.html"));
+}
+
 IN_PROC_BROWSER_TEST_F(NaClBrowserTestPnacl,
                        MAYBE_PNACL(PnaclNMFOptionsO0)) {
   RunLoadTest(FILE_PATH_LITERAL("pnacl_options.html?use_nmf=o_0"));
 }
 
-// Test Subzero. Subzero is triggered by the O0 option so reuse that test
-// pexe and test harness.
+// Test Subzero. Subzero is triggered by the O0 option so reuse
+// test harnesses that use "optlevel": 0.
 IN_PROC_BROWSER_TEST_F(NaClBrowserTestPnaclSubzero,
                        MAYBE_PNACL(PnaclNMFOptionsO0)) {
   RunLoadTest(FILE_PATH_LITERAL("pnacl_options.html?use_nmf=o_0"));