Implement requestIdleCallback API

Source/core/frame/LocalDOMWindow.cpp

Index: Source/core/frame/LocalDOMWindow.cpp
diff --git a/Source/core/frame/LocalDOMWindow.cpp b/Source/core/frame/LocalDOMWindow.cpp
index 6f4e6ec346538fefab490d39a3bed0beb2a49eda..14eeedf372b70f825972904f7cfa4766a17d9ea9 100644
--- a/Source/core/frame/LocalDOMWindow.cpp
+++ b/Source/core/frame/LocalDOMWindow.cpp
@@ -1369,6 +1369,19 @@ void LocalDOMWindow::cancelAnimationFrame(int id)
         d->cancelAnimationFrame(id);
 }
 
+int LocalDOMWindow::requestIdleFrame(IdleRequestCallback* callback)
+{
+    if (Document* d = document())

[esprehn, 2015/06/10 07:11:42]

document, don't abbreviate.

[rmcilroy, 2015/06/10 18:32:41]

I couldn't call this document because of the function of the same name - instead
I just removed the local variable and used document() in both places (also in
rAF).

+        return d->requestIdleFrame(callback);
+    return 0;
+}
+
+void LocalDOMWindow::cancelIdleFrame(int id)
+{
+    if (Document* d = document())

[esprehn, 2015/06/10 07:11:42]

ditto, also can this really be null? I don't think it can.

[rmcilroy, 2015/06/10 18:32:41]

clearDocument resets m_document. I'm not sure on whether this can have happened
before a requestIdleFrame/cancelIdleFrame though (I was following the same
pattern as rAF above).

+        d->cancelIdleFrame(id);
+}
+
 DOMWindowCSS* LocalDOMWindow::css() const
 {
     if (!m_css)