Rewrite double.parse.

runtime/lib/integers_patch.dart

Index: runtime/lib/integers_patch.dart
diff --git a/runtime/lib/integers_patch.dart b/runtime/lib/integers_patch.dart
index 05d47cf9706ab72195f810be87dd9fd8012f550a..b6ea6e134852b845d71eee72ea7f25d8a09efef2 100644
--- a/runtime/lib/integers_patch.dart
+++ b/runtime/lib/integers_patch.dart
@@ -7,26 +7,20 @@
 
 patch class int {
 
-  static bool _isWhitespace(int codePoint) {
-    return
-      (codePoint == 32) || // Space.
-      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
-  }
-
   static int _tryParseSmi(String str) {
     if (str.isEmpty) return null;
     var ix = 0;
     var endIx = str.length - 1;
     // Find first and last non-whitespace.
     while (ix <= endIx) {
-      if (!_isWhitespace(str.codeUnitAt(ix))) break;
+      if (!str._isWhitespace(str.codeUnitAt(ix))) break;
       ix++;
     }
     if (endIx < ix) {
       return null;  // Empty.
     }
     while (endIx > ix) {
-      if (!_isWhitespace(str.codeUnitAt(endIx))) break;
+      if (!str._isWhitespace(str.codeUnitAt(endIx))) break;
       endIx--;
     }