Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/tools/reserved_dart_keywords.dart

Index: third_party/pkg/angular/lib/tools/reserved_dart_keywords.dart
diff --git a/third_party/pkg/angular/lib/tools/reserved_dart_keywords.dart b/third_party/pkg/angular/lib/tools/reserved_dart_keywords.dart
new file mode 100644
index 0000000000000000000000000000000000000000..5d009f5fcae5869d7ead857fbc2bf8f3385ddbdd
--- /dev/null
+++ b/third_party/pkg/angular/lib/tools/reserved_dart_keywords.dart
@@ -0,0 +1,10 @@
+library reserved_dart_keywords;
+
+// From https://www.dartlang.org/docs/spec/latest/dart-language-specification.html#h.huusvrzea3q
+List<String> RESERVED_DART_KEYWORDS = [
+    "assert", "break", "case", "catch", "class", "const", "continue",
+    "default", "do", "else", "enum", "extends", "false", "final",
+    "finally", "for", "if", "in", "is", "new", "null", "rethrow",
+    "return", "super", "switch", "this", "throw", "true", "try",
+    "var", "void", "while", "with"];
+isReserved(String key) => RESERVED_DART_KEYWORDS.contains(key);