Fixing ArrayBuffer et al on IE.

tools/dom/templates/html/dart2js/impl_ArrayBuffer.darttemplate

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of $LIBRARYNAME;
+
+/// @domName $DOMNAME$ANNOTATIONS
+class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$!MEMBERS
+  /// @domName ArrayBuffer.slice;
+  ArrayBuffer slice(int begin, [int end]) {
+    // IE10 supports ArrayBuffers but does not have the slice method.
+    if (JS('bool', '!!#.slice', this)) {
+      if (?end) {
+        return JS('ArrayBuffer', '#.slice(#, #)', this, begin, end);
+      }
+      return JS('ArrayBuffer', '#.slice(#)', this, begin);
+    } else {
+      var start = begin;
+      // Negative values go from end.
+      if (start < 0) {
+        start = this.byteLength + start;
+      }
+      var finish = ?end ? min(end, byteLength) : byteLength;
+      if (finish < 0) {
+        finish = this.byteLength + finish;
+      }
+      var length = max(finish - start, 0);
+
+      var clone = new Int8Array(length);
+      var source = new Int8Array.fromBuffer(this, start);
+      for (var i = 0; i < length; ++i) {
+        clone[i] = source[i];
+      }
+      return clone.buffer;
+    }
+  }
+}