Update Analyzer tests to pass NonExistingSource rather than null

Change-Id: I770d50a31230e7e3fdabecf4cbffc6fee76e1fb5
Reviewed-on: https://dart-review.googlesource.com/57020
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Dan Rubel <danrubel@google.com>
diff --git a/pkg/analyzer/lib/src/generated/source.dart b/pkg/analyzer/lib/src/generated/source.dart
index d693693..c7e14c8 100644
--- a/pkg/analyzer/lib/src/generated/source.dart
+++ b/pkg/analyzer/lib/src/generated/source.dart
@@ -272,6 +272,9 @@
  * An implementation of an non-existing [Source].
  */
 class NonExistingSource extends Source {
+  static final unknown = new NonExistingSource(
+      '/unknown.dart', pathos.toUri('/unknown.dart'), UriKind.FILE_URI);
+
   @override
   final String fullName;
 
diff --git a/pkg/analyzer/test/generated/parser_test.dart b/pkg/analyzer/test/generated/parser_test.dart
index f324c87..35b6075 100644
--- a/pkg/analyzer/test/generated/parser_test.dart
+++ b/pkg/analyzer/test/generated/parser_test.dart
@@ -10053,7 +10053,7 @@
     listener ??= AnalysisErrorListener.NULL_LISTENER;
     Scanner scanner = new Scanner(null, new CharSequenceReader(code), listener);
     Token token = scanner.tokenize();
-    Parser parser = new Parser(null, listener);
+    Parser parser = new Parser(NonExistingSource.unknown, listener);
     parser.enableOptionalNewAndConst = enableOptionalNewAndConst;
     CompilationUnit unit = parser.parseCompilationUnit(token);
     unit.lineInfo = new LineInfo(scanner.lineStarts);
@@ -13173,7 +13173,7 @@
   }
 
   void test_Parser() {
-    expect(new Parser(null, null), isNotNull);
+    expect(new Parser(NonExistingSource.unknown, null), isNotNull);
   }
 
   void test_parseTypeName_parameterized_nullable() {
diff --git a/pkg/analyzer/test/generated/utilities_test.dart b/pkg/analyzer/test/generated/utilities_test.dart
index f960be0..010ae47 100644
--- a/pkg/analyzer/test/generated/utilities_test.dart
+++ b/pkg/analyzer/test/generated/utilities_test.dart
@@ -1184,7 +1184,7 @@
     CharSequenceReader reader = new CharSequenceReader(code);
     Scanner scanner = new Scanner(null, reader, listener);
     Token token = scanner.tokenize();
-    Parser parser = new Parser(null, listener);
+    Parser parser = new Parser(NonExistingSource.unknown, listener);
     CompilationUnit unit = parser.parseCompilationUnit(token);
     expect(unit, isNotNull);
     listener.assertNoErrors();
diff --git a/pkg/analyzer/test/src/summary/summarize_ast_test.dart b/pkg/analyzer/test/src/summary/summarize_ast_test.dart
index f95085b..d78d8a7 100644
--- a/pkg/analyzer/test/src/summary/summarize_ast_test.dart
+++ b/pkg/analyzer/test/src/summary/summarize_ast_test.dart
@@ -314,7 +314,8 @@
     Scanner scanner =
         new Scanner(null, reader, AnalysisErrorListener.NULL_LISTENER);
     Token token = scanner.tokenize();
-    Parser parser = new Parser(null, AnalysisErrorListener.NULL_LISTENER);
+    Parser parser = new Parser(
+        NonExistingSource.unknown, AnalysisErrorListener.NULL_LISTENER);
     CompilationUnit unit = parser.parseCompilationUnit(token);
     unit.lineInfo = new LineInfo(scanner.lineStarts);
     return unit;