[Specs] Remove all the obsolete specs.

sky/specs/builtins.md

Index: sky/specs/builtins.md
diff --git a/sky/specs/builtins.md b/sky/specs/builtins.md
deleted file mode 100644
index 90ac3dbc3f5a8e23e200ea7dccf30395693e4227..0000000000000000000000000000000000000000
--- a/sky/specs/builtins.md
+++ /dev/null
@@ -1,112 +0,0 @@
-Built-In Elements
-=================
-
-```dart
-SKY MODULE
-
-<script>
-import 'dart:sky';
-
-class ImportElement extends Element {
-  ImportElement = Element;
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class TemplateElement extends Element {
-  TemplateElement = Element;
-
-  // TODO(ianh): convert <template> to using a token stream instead of a Fragment
-
-  external Fragment get content; // O(1)
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class ScriptElement extends Element {
-  ScriptElement = Element;
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class StyleElement extends Element {
-  StyleElement = Element;
-
-  external List<Rule> getRules(); // O(N) in rules
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class ContentElement extends Element {
-  ContentElement = Element;
-
-  external List<Node> getDistributedNodes(); // O(N) in distributed nodes
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class ImgElement extends Element {
-  ImgElement = Element;
-
-  @override
-  Type getLayoutManager() => ImgElementLayoutManager; // O(1)
-}
-
-class DivElement extends Element {
-  DivElement = Element;
-}
-
-class SpanElement extends Element {
-  SpanElement = Element;
-}
-
-class IframeElement extends Element {
-  IframeElement = Element;
-
-  @override
-  Type getLayoutManager() => IframeElementLayoutManager; // O(1)
-}
-
-class TElement extends Element {
-  TElement = Element;
-}
-
-class AElement extends Element {
-  AElement = Element;
-}
-
-class TitleElement extends Element {
-  TitleElement = Element;
-
-  @override
-  Type getLayoutManager() => null; // O(1)
-}
-
-class _ErrorElement extends Element {
-  _ErrorElement._create();
-
-  @override
-  Type getLayoutManager() => _ErrorElementLayoutManager; // O(1)
-}
-
-void _init(script) {
-  module.registerElement('import', ImportElement);
-  module.registerElement('template', TemplateElement);
-  module.registerElement('script', ScriptElement);
-  module.registerElement('style', StyleElement);
-  module.registerElement('content', ContentElement);
-  module.registerElement('img', ImgElement);
-  module.registerElement('div', DivElement);
-  module.registerElement('span', SpanElement);
-  module.registerElement('iframe', IframeElement);
-  module.registerElement('t', TElement);
-  module.registerElement('a', AElement);
-  module.registerElement('title', TitleElement);
-}
-</script>
-```