First implementation of lazily cached accessor for DOM attributes.

third_party/WebKit/Source/core/html/HTMLElement.idl

Index: third_party/WebKit/Source/core/html/HTMLElement.idl
diff --git a/third_party/WebKit/Source/core/html/HTMLElement.idl b/third_party/WebKit/Source/core/html/HTMLElement.idl
index 9c316ec8df80d81623b28f300ba9d1770d66f318..021e4c42b0b7c91df12fb51ef4a408c7cb1dffbd 100644
--- a/third_party/WebKit/Source/core/html/HTMLElement.idl
+++ b/third_party/WebKit/Source/core/html/HTMLElement.idl
@@ -22,8 +22,8 @@
 [HTMLConstructor]
 interface HTMLElement : Element {
     // metadata attributes
-    [CEReactions, Reflect] attribute DOMString title;
-    [CEReactions, Reflect] attribute DOMString lang;
+    [CEReactions, Reflect, CachedAccessor=Lazy] attribute DOMString title;

[Yuki, 2017/05/09 06:06:31]

Just curious, are |title| and |lang| so important?

I understand |id| is quite often used and worth using the cached accessor.  But
I didn't imagine that |title| and |lang| are heavily used.

[nverne, 2017/05/10 02:11:49]

haraken@ said these were good test cases for the mechanism itself. This plan is
to migrate lots of DOM properties to lazy caching, and these three are a
reasonable start. We can always revisit the choices of which attributes deserve
caching in future.

+    [CEReactions, Reflect, CachedAccessor=Lazy] attribute DOMString lang;
     [CEReactions] attribute boolean translate;
     [CEReactions] attribute DOMString dir;
     [SameObject, PerWorldBindings] readonly attribute DOMStringMap dataset;