Fix some strong mode warnings in the parser.

R=jmesserly@google.com

Review URL: https://codereview.chromium.org//1375713005 .
diff --git a/pkgs/yaml/CHANGELOG.md b/pkgs/yaml/CHANGELOG.md
index f845707..21fbf36 100644
--- a/pkgs/yaml/CHANGELOG.md
+++ b/pkgs/yaml/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.1.7
+
+* Fix more strong mode warnings.
+
 ## 2.1.6
 
 * Fix two analysis issues with DDC's strong mode.
diff --git a/pkgs/yaml/lib/src/parser.dart b/pkgs/yaml/lib/src/parser.dart
index 136247b..b44043a 100644
--- a/pkgs/yaml/lib/src/parser.dart
+++ b/pkgs/yaml/lib/src/parser.dart
@@ -260,24 +260,24 @@
     var anchor;
     var tagToken;
     var span = token.span.start.pointSpan();
-    parseAnchor() {
+    parseAnchor(token) {
       anchor = token.name;
       span = span.expand(token.span);
-      token = _scanner.advance();
+      return _scanner.advance();
     }
 
-    parseTag() {
+    parseTag(token) {
       tagToken = token;
       span = span.expand(token.span);
-      token = _scanner.advance();
+      return _scanner.advance();
     }
 
     if (token is AnchorToken) {
-      parseAnchor();
-      if (token is TagToken) parseTag();
+      token = parseAnchor(token);
+      if (token is TagToken) token = parseTag(token);
     } else if (token is TagToken) {
-      parseTag();
-      if (token is AnchorToken) parseAnchor();
+      token = parseTag(token);
+      if (token is AnchorToken) token = parseAnchor(token);
     }
 
     var tag;
diff --git a/pkgs/yaml/pubspec.yaml b/pkgs/yaml/pubspec.yaml
index 9d92334..98f2e29 100644
--- a/pkgs/yaml/pubspec.yaml
+++ b/pkgs/yaml/pubspec.yaml
@@ -1,5 +1,5 @@
 name: yaml
-version: 2.1.6
+version: 2.1.7-dev
 author: "Dart Team <misc@dartlang.org>"
 homepage: https://github.com/dart-lang/yaml
 description: A parser for YAML.