Remove generated directories with 100s of files.

client/html/generated/html/dartium/CSSMediaRule.dart

Index: client/html/generated/html/dartium/CSSMediaRule.dart
diff --git a/client/html/generated/html/dartium/CSSMediaRule.dart b/client/html/generated/html/dartium/CSSMediaRule.dart
deleted file mode 100644
index 74ab8d9781547a4222c5828e23e075563c0d1ebf..0000000000000000000000000000000000000000
--- a/client/html/generated/html/dartium/CSSMediaRule.dart
+++ /dev/null
@@ -1,17 +0,0 @@
-
-class _CSSMediaRuleImpl extends _CSSRuleImpl implements CSSMediaRule {
-  _CSSMediaRuleImpl._wrap(ptr) : super._wrap(ptr);
-
-  CSSRuleList get cssRules() => _wrap(_ptr.cssRules);
-
-  MediaList get media() => _wrap(_ptr.media);
-
-  void deleteRule(int index) {
-    _ptr.deleteRule(_unwrap(index));
-    return;
-  }
-
-  int insertRule(String rule, int index) {
-    return _wrap(_ptr.insertRule(_unwrap(rule), _unwrap(index)));
-  }
-}