Optimize DDC private library files.

pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart

Index: pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart b/pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart
index efcea7c971a0d1f046cc863af4cd9b736eaa32ad..937a7ff1281429792dd6767854230e6d28cc6436 100644
--- a/pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart
+++ b/pkg/dev_compiler/tool/input_sdk/private/regexp_helper.dart
@@ -7,8 +7,6 @@ part of dart._js_helper;
 // Helper method used by internal libraries.
 regExpGetNative(JSSyntaxRegExp regexp) => regexp._nativeRegExp;
 
-List<String> _stringList(List l) => l == null ? l : new JSArray<String>.of(l);
-
 /**
  * Returns a native version of the RegExp with the global flag set.
  *
@@ -36,7 +34,8 @@ regExpGetGlobalNative(JSSyntaxRegExp regexp) {
  */
 int regExpCaptureCount(JSSyntaxRegExp regexp) {
   var nativeAnchoredRegExp = regexp._nativeAnchoredVersion;
-  var match = JS('JSExtendableArray', "#.exec('')", nativeAnchoredRegExp);
+  JSExtendableArray match =
+      JS('JSExtendableArray', "#.exec('')", nativeAnchoredRegExp);
   // The native-anchored regexp always have one capture more than the original,
   // and always matches the empty string.
   return match.length - 2;
@@ -76,9 +75,8 @@ class JSSyntaxRegExp implements RegExp {
   bool get _isMultiLine => JS("bool", "#.multiline", _nativeRegExp);
   bool get _isCaseSensitive => JS("bool", "!#.ignoreCase", _nativeRegExp);
 
-  static makeNative(
-      String source, bool multiLine, bool caseSensitive, bool global) {
-    checkString(source);
+  static makeNative(@nullCheck String source, bool multiLine,
+      bool caseSensitive, bool global) {
     String m = multiLine ? 'm' : '';
     String i = caseSensitive ? '' : 'i';
     String g = global ? 'g' : '';
@@ -105,15 +103,15 @@ class JSSyntaxRegExp implements RegExp {
     throw new FormatException("Illegal RegExp pattern: $source, $errorMessage");
   }
 
-  Match firstMatch(String string) {
-    List m = JS('JSExtendableArray|Null', r'#.exec(#)', _nativeRegExp,
-        checkString(string));
+  Match firstMatch(@nullCheck String string) {
+    List m = JS('JSExtendableArray|Null', r'#.exec(#)', _nativeRegExp, string);
     if (m == null) return null;
-    return new _MatchImplementation(this, _stringList(m));
+    return new _MatchImplementation(this, new JSArray<String>.of(m));
   }
 
-  bool hasMatch(String string) {
-    return JS('bool', r'#.test(#)', _nativeRegExp, checkString(string));
+  @notNull
+  bool hasMatch(@nullCheck String string) {
+    return JS('bool', r'#.test(#)', _nativeRegExp, string);
   }
 
   String stringMatch(String string) {
@@ -122,9 +120,8 @@ class JSSyntaxRegExp implements RegExp {
     return null;
   }
 
-  Iterable<Match> allMatches(String string, [int start = 0]) {
-    checkString(string);
-    checkInt(start);
+  Iterable<Match> allMatches(@nullCheck String string,
+      [@nullCheck int start = 0]) {
     if (start < 0 || start > string.length) {
       throw new RangeError.range(start, 0, string.length);
     }
@@ -136,7 +133,7 @@ class JSSyntaxRegExp implements RegExp {
     JS("void", "#.lastIndex = #", regexp, start);
     List match = JS("JSExtendableArray|Null", "#.exec(#)", regexp, string);
     if (match == null) return null;
-    return new _MatchImplementation(this, _stringList(match));
+    return new _MatchImplementation(this, new JSArray<String>.of(match));
   }
 
   Match _execAnchored(String string, int start) {
@@ -148,7 +145,7 @@ class JSSyntaxRegExp implements RegExp {
     // match at the start position.
     if (match[match.length - 1] != null) return null;
     match.length -= 1;
-    return new _MatchImplementation(this, _stringList(match));
+    return new _MatchImplementation(this, new JSArray<String>.of(match));
   }
 
   Match matchAsPrefix(String string, [int start = 0]) {