Add getter for hasTerminal, terminalColumns and terminalLines on stdout.

tests/standalone/io/stdin_sync_test.dart

Index: tests/standalone/io/stdin_sync_test.dart
diff --git a/tests/standalone/io/stdin_sync_test.dart b/tests/standalone/io/stdin_sync_test.dart
index 03e794cdd2501e2d9d6ecd9e7539b951106d8dd6..97c4b58460e81ed71c264645b490fed667008bf1 100644
--- a/tests/standalone/io/stdin_sync_test.dart
+++ b/tests/standalone/io/stdin_sync_test.dart
@@ -44,6 +44,7 @@ void testReadByte() {
   test("hej", ['hej']);
 }
 
+
 void testEchoMode() {
   stdin.echoMode = true;
   Expect.isTrue(stdin.echoMode);
@@ -55,6 +56,7 @@ void testEchoMode() {
   }
 }
 
+
 void testLineMode() {
   stdin.lineMode = true;
   Expect.isTrue(stdin.lineMode);
@@ -70,7 +72,7 @@ void testLineMode() {
 void main() {
   testReadByte();
 
-  // testEchoMode and testLineMode is an developer-interactive test, thus not
+  // testEchoMode and testLineMode is developer-interactive tests, thus not
   // enabled.
   //testEchoMode();
   //testLineMode();