A couple of lint cleanups (dart-lang/markdown#209)

pkgs/markdown/lib/src/extension_set.dart

diff --git a/pkgs/markdown/lib/src/extension_set.dart b/pkgs/markdown/lib/src/extension_set.dart
index 12be92b..363597c 100644
--- a/pkgs/markdown/lib/src/extension_set.dart
+++ b/pkgs/markdown/lib/src/extension_set.dart
@@ -4,8 +4,8 @@
 /// ExtensionSets provide a simple grouping mechanism for common Markdown
 /// flavors.
 ///
-/// For example, the [gitHub] set of syntax extensions allows users to output
-/// HTML from their Markdown in a similar fashion to GitHub's parsing.
+/// For example, the [gitHubFlavored] set of syntax extensions allows users to
+/// output HTML from their Markdown in a similar fashion to GitHub's parsing.
 class ExtensionSet {
   /// The [ExtensionSet.none] extension set renders Markdown similar to
   /// [Markdown.pl].

pkgs/markdown/tool/dartdoc-compare.dart

diff --git a/pkgs/markdown/tool/dartdoc-compare.dart b/pkgs/markdown/tool/dartdoc-compare.dart
index 63ed868..be68cbd 100644
--- a/pkgs/markdown/tool/dartdoc-compare.dart
+++ b/pkgs/markdown/tool/dartdoc-compare.dart
@@ -94,7 +94,7 @@
     _doInPath(dartdocDir, () {
       var returnCode = _updateDartdocPubspec(markdownRef);
       if (returnCode != 0) {
-        throw "Could not update dartdoc's pubspec!";
+        throw new Exception("Could not update dartdoc's pubspec!");
       }
     });
     return _doInPath(path, () {