Avoid reattachWhitespaceSiblings when renderer does not change.

If the renderer is null before and after the style recalc, there is no need
to reattach whitespace siblings. It is necessary to check for needsAttach()
since the old renderer might have been detached by lazyReattachIfAttached(),
for instance.

BUG=340213

Review URL: https://codereview.chromium.org/188543002

git-svn-id: svn://svn.chromium.org/blink/trunk@168668 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove deprecated focusedNode APIs

Remove WebDocument::focusedNode and WebView::clearFocusedNode APIs
as they are deprecated and not used anymore.

BUG=258763

Review URL: https://codereview.chromium.org/179293007

git-svn-id: svn://svn.chromium.org/blink/trunk@168669 bbb929c8-8fbe-4397-9dbb-9b2b20218538