Use FormatMessageW for Windows error messages to handle internationalized messages correctly.

tests/standalone/io/directory_error_test.dart

Index: tests/standalone/io/directory_error_test.dart
diff --git a/tests/standalone/io/directory_error_test.dart b/tests/standalone/io/directory_error_test.dart
index cf90f91f149fff0ff87d63d5699869816560efb3..fecb2231863f7d83feaafe508ccf1b46594b24ad 100644
--- a/tests/standalone/io/directory_error_test.dart
+++ b/tests/standalone/io/directory_error_test.dart
@@ -17,15 +17,10 @@ bool checkCreateInNonExistentFileException(e) {
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Creation failed") != -1);
   if (Platform.operatingSystem == "linux") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "macos") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "windows") {
-    Expect.isTrue(
-        e.toString().indexOf(
-            "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
@@ -49,18 +44,11 @@ void testCreateInNonExistent(Directory temp, Function done) {
 bool checkCreateTempInNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
-  Expect.isTrue(e.toString().indexOf(
-      "Creation of temporary directory failed") != -1);
   if (Platform.operatingSystem == "linux") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "macos") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "windows") {
-    Expect.isTrue(
-        e.toString().indexOf(
-            "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
@@ -84,16 +72,6 @@ void testCreateTempInNonExistent(Directory temp, Function done) {
 bool checkDeleteNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
-  Expect.isTrue(e.toString().indexOf("Deletion failed") != -1);
-  if (Platform.operatingSystem == "linux") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
-  } else if (Platform.operatingSystem == "macos") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
-  } else if (Platform.operatingSystem == "windows") {
-    Expect.isTrue(
-        e.toString().indexOf(
-            "The system cannot find the file specified") != -1);
-  }
   // File not not found has error code 2 on all supported platforms.
   Expect.equals(2, e.osError.errorCode);
 
@@ -119,15 +97,10 @@ bool checkDeleteRecursivelyNonExistentFileException(e) {
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Deletion failed") != -1);
   if (Platform.operatingSystem == "linux") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "macos") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "windows") {
-    Expect.isTrue(
-        e.toString().indexOf(
-            "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
@@ -153,15 +126,10 @@ bool checkListNonExistentFileException(e) {
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Directory listing failed") != -1);
   if (Platform.operatingSystem == "linux") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "macos") {
-    Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
   } else if (Platform.operatingSystem == "windows") {
-    Expect.isTrue(
-        e.toString().indexOf(
-            "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }