Add VM internal Dart class 'ClassID' used to manage class-ids of known classes. Next CL: add consta…

runtime/lib/string_patch.dart

Index: runtime/lib/string_patch.dart
===================================================================
--- runtime/lib/string_patch.dart	(revision 37566)
+++ runtime/lib/string_patch.dart	(working copy)
@@ -54,7 +54,7 @@
   static String createFromCharCodes(Iterable<int> charCodes) {
     if (charCodes != null) {
       // TODO(srdjan): Also skip copying of wide typed arrays.
-      final ccid = charCodes._cid;
+      final ccid = ClassID.getID(charCodes);
       bool isOneByteString = false;
       if ((ccid != _List._classId) &&
           (ccid != _GrowableList._classId) &&
@@ -510,7 +510,7 @@
     int totalLength = 0;
     for (int i = 0; i < numValues; i++) {
       var s = values[i].toString();
-      if (isOneByteString && (s._cid == _OneByteString._classId)) {
+      if (isOneByteString && (ClassID.getID(s) == _OneByteString._classId)) {
         totalLength += s.length;
       } else {
         isOneByteString = false;
@@ -625,7 +625,7 @@
 
 
 class _OneByteString extends _StringBase implements String {
-  static final int _classId = "A"._cid;
+  static final int _classId = ClassID.getID("A");
 
   factory _OneByteString._uninstantiable() {
     throw new UnsupportedError(
@@ -649,7 +649,8 @@
       native "OneByteString_splitWithCharCode";
 
   List<String> split(Pattern pattern) {
-    if ((pattern._cid == _OneByteString._classId) && (pattern.length == 1)) {
+    if ((ClassID.getID(pattern) == _OneByteString._classId) &&
+        (pattern.length == 1)) {
       return _splitWithCharCode(pattern.codeUnitAt(0));
     }
     return super.split(pattern);
@@ -677,7 +678,7 @@
 
   int indexOf(Pattern pattern, [int start = 0]) {
     // Specialize for single character pattern.
-    final pCid = pattern._cid;
+    final pCid = ClassID.getID(pattern);
     if ((pCid == _OneByteString._classId) ||
         (pCid == _TwoByteString._classId) ||
         (pCid == _ExternalOneByteString._classId)) {
@@ -699,7 +700,7 @@
   }
 
   bool contains(Pattern pattern, [int start = 0]) {
-    final pCid = pattern._cid;
+    final pCid = ClassID.getID(pattern);
     if ((pCid == _OneByteString._classId) ||
         (pCid == _TwoByteString._classId) ||
         (pCid == _ExternalOneByteString._classId)) {
@@ -736,7 +737,7 @@
   }
 
   String padLeft(int width, [String padding = ' ']) {
-    int padCid = padding._cid;
+    int padCid = ClassID.getID(padding);
     if (padCid != _OneByteString._classId &&
         padCid != _ExternalOneByteString._classId) {
       return super.padLeft(width, padding);
@@ -767,7 +768,7 @@
   }
 
   String padRight(int width, [String padding = ' ']) {
-    int padCid = padding._cid;
+    int padCid = ClassID.getID(padding);
     if (padCid != _OneByteString._classId &&
         padCid != _ExternalOneByteString._classId) {
       return super.padRight(width, padding);
@@ -906,7 +907,7 @@
 
 
 class _TwoByteString extends _StringBase implements String {
-  static final int _classId = "\u{FFFF}"._cid;
+  static final int _classId = ClassID.getID("\u{FFFF}");
 
   factory _TwoByteString._uninstantiable() {
     throw new UnsupportedError(