Improve the event handling for string input stream

tools/testing/dart/status_file_parser.dart

Index: tools/testing/dart/status_file_parser.dart
diff --git a/tools/testing/dart/status_file_parser.dart b/tools/testing/dart/status_file_parser.dart
index 38afda6fbe2979e3e53933548a05c61d3cc86d75..40d5ed7c6d86b640846e1e73b33d3cd7dc33ecfd 100644
--- a/tools/testing/dart/status_file_parser.dart
+++ b/tools/testing/dart/status_file_parser.dart
@@ -45,20 +45,25 @@ String getDirname(String path) =>
 
 void ReadTestExpectationsInto(TestExpectations expectations,
                               String statusFilePath,
-                              environment) {
+                              environment,
+                              onDone) {
   List<Section> sections = new List<Section>();
-  ReadConfigurationInto(statusFilePath, sections);
 
-  for (Section section in sections) {
-    if (section.isEnabled(environment)) {
-      for (var rule in section.testRules) {
-        expectations.addRule(rule, environment);
+  void sectionsRead() {
+    for (Section section in sections) {
+      if (section.isEnabled(environment)) {
+        for (var rule in section.testRules) {
+          expectations.addRule(rule, environment);
+        }
       }
     }
+    onDone();
   }
+
+  ReadConfigurationInto(statusFilePath, sections, sectionsRead);
 }
 
-void ReadConfigurationInto(path, sections) {
+void ReadConfigurationInto(path, sections, onDone) {
   File file = new File(getFilename(path));
   if (!file.existsSync()) return;  // TODO(whesse): Handle missing file.
   FileInputStream file_stream = file.openInputStream();
@@ -68,6 +73,7 @@ void ReadConfigurationInto(path, sections) {
   sections.add(current);
   String prefix = "";
 
+  lines.lineHandler = () {
   String line;

[Mads Ager (google), 2011/12/09 13:09:33]

Indent line 77 to 113.

[Søren Gjesse, 2011/12/09 13:36:43]

Done.

   while ((line = lines.readLine()) != null) {
     Match match = StripComment.firstMatch(line);
@@ -105,8 +111,12 @@ void ReadConfigurationInto(path, sections) {
 
     print("unmatched line: $line");
   }
+  };
 
-  file_stream.close();
+  lines.closeHandler = () {
+    file_stream.close();
+    onDone();
+  };
 }