Extract named items caches in HTMLCollection as a class

Extract named items caches in HTMLCollection as a class
https://bugs.webkit.org/show_bug.cgi?id=129365

Reviewed by Antti Koivisto.

Extracted CollectionNamedElementCache, like CollectionIndexCache, out of HTMLCollection.
We can move more named item related functions into this class in the future.

HTMLCollection's member variables m_isNameCacheValid, m_idCache, and m_nameCache were replaced by
a single unique_ptr that holds an instance of CollectionNamedElementCache since this object rarely
exists in most HTMLCollections.

Also removed m_isItemRefElementsCacheValid since it was only used by Microdata API removed in r153772
and renamed a whole bunch of member functions and variables for consistency.

* dom/Document.cpp:
(WebCore::Document::collectionCachedIdNameMap):
(WebCore::Document::collectionWillClearIdNameMap):
* dom/Document.h:
* dom/NodeRareData.h:
(WebCore::NodeListsNodeData::adoptDocument):
* html/HTMLAllCollection.cpp:
(WebCore::HTMLAllCollection::namedItemWithIndex):
* html/HTMLCollection.cpp:
(WebCore::HTMLCollection::HTMLCollection):
(WebCore::HTMLCollection::~HTMLCollection):
(WebCore::HTMLCollection::invalidateCache):
(WebCore::HTMLCollection::invalidateNamedElementCache): Renamed from invalidateIdNameCacheMaps.
(WebCore::HTMLCollection::namedItem):
(WebCore::HTMLCollection::updateNamedElementCache): Renamed from updateNameCache.
(WebCore::HTMLCollection::namedItems):

* html/HTMLCollection.h:
(WebCore::CollectionNamedElementCache::findElementsWithId): Renamed from HTMLCollection::idCache.
(WebCore::CollectionNamedElementCache::findElementsWithName): Renamed from HTMLCollection::nameCache.
(WebCore::CollectionNamedElementCache::appendIdCache): Moved from HTMLCollection.
(WebCore::CollectionNamedElementCache::appendNameCache): Ditto.
(WebCore::CollectionNamedElementCache::find): Ditto.
(WebCore::CollectionNamedElementCache::append): Ditto.

(WebCore::HTMLCollection::invalidateCache):
(WebCore::HTMLCollection::hasNamedElementCache): Renamed from hasIdNameCache.
(WebCore::HTMLCollection::createNameItemCache): Added.
(WebCore::HTMLCollection::namedItemCaches): Added.

* html/HTMLFormControlsCollection.cpp:
(WebCore::HTMLFormControlsCollection::updateNamedElementCache):
* html/HTMLFormControlsCollection.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@164772 268f45cc-cd09-0410-ab3c-d52691b4dbfc