Recognize EMSGSIZE as non-fatal on OS X.

chrome/test/page_cycler/page_cycler_test.cc

Index: chrome/test/page_cycler/page_cycler_test.cc
diff --git a/chrome/test/page_cycler/page_cycler_test.cc b/chrome/test/page_cycler/page_cycler_test.cc
index 845391a25206de371e6a6c2c1f50ed18f7af4fac..099beab662b19fca81e6a5b1074fda960a85630c 100644
--- a/chrome/test/page_cycler/page_cycler_test.cc
+++ b/chrome/test/page_cycler/page_cycler_test.cc
@@ -184,7 +184,8 @@ class PageCyclerTest : public UITest {
     test_path = test_path.Append(FILE_PATH_LITERAL("data"));
     test_path = test_path.Append(FILE_PATH_LITERAL("page_cycler"));
     test_path = test_path.AppendASCII(name);
-    ASSERT_TRUE(file_util::PathExists(test_path)) << "Missing test data";
+    ASSERT_TRUE(file_util::PathExists(test_path)) << "Missing test data"
+                                                  << test_path.value();
 
 #if defined(OS_MACOSX)
     PopulateUBC(test_path);