Ignore absence of DOCTYPE in HTML files.

pkg/analyzer/test/src/context/context_test.dart

Index: pkg/analyzer/test/src/context/context_test.dart
diff --git a/pkg/analyzer/test/src/context/context_test.dart b/pkg/analyzer/test/src/context/context_test.dart
index 0544bf56789d0e1808811cd27d21d7b1d1996e64..d4d31319514ec9f35a2c7f811383c3ea1f1cba4c 100644
--- a/pkg/analyzer/test/src/context/context_test.dart
+++ b/pkg/analyzer/test/src/context/context_test.dart
@@ -905,7 +905,7 @@ class A {
     List<AnalysisError> errors = errorInfo.errors;
     expect(errors, hasLength(0));
     errors = context.computeErrors(source);
-    expect(errors, hasLength(3));
+    expect(errors, hasLength(2));
   }
 
   void test_getHtmlFilesReferencing_html() {
@@ -1718,9 +1718,9 @@ void g() { f(null); }''');
 </script></body></html>''');
     _analyzeAll_assertFinished();
     context.computeErrors(htmlSource);
-    expect(_hasAnalysisErrorWithErrorSeverity(context.getErrors(htmlSource)),
-        isTrue,
-        reason: "htmlSource has an error");
+//    expect(_hasAnalysisErrorWithErrorSeverity(context.getErrors(htmlSource)),
+//        isTrue,
+//        reason: "htmlSource has an error");
     // add libB.dart and analyze
     Source libBSource = addSource("/libB.dart", "library libB;");
     _analyzeAll_assertFinished();