https://bugs.webkit.org/show_bug.cgi?id=110652

Reviewed by Brady Eidson.

Source/WebCore: 

* WebCore.exp.in: Added WebCore::HistoryItem::isInPageCache and hasCachedPageExpired.
* history/CachedPage.cpp: Add a data member, m_expirationTime, and a function, hasExpired().
* history/CachedPage.h:
* history/HistoryItem.cpp:
(WebCore::HistoryItem::hasCachedPageExpired): Added. returns m_cachedPage's expiration state.
* history/HistoryItem.h:
* history/PageCache.cpp:
(WebCore::PageCache::get):  Address the fixme about not using WebKitBackForwardCacheExpirationIntervalKey. 
* page/Settings.in: Add backForwardCacheExpirationInterval to the automatically generated setters for Settings.

Source/WebKit/mac: 

* History/WebHistoryItem.mm:
(-[WebHistoryItem _isInPageCache]): Added. Just calls and returns core imple's function. 
(-[WebHistoryItem _hasCachedPageExpired]): Same thing. 
* History/WebHistoryItemPrivate.h:
* WebView/WebPreferences.mm:
(-[WebPreferences _backForwardCacheExpirationInterval]): Address fixme, now that WebCore::Settings
has getters and setters with default value.
* WebView/WebView.mm:
(-[WebView _preferencesChanged:]): call setBackForwardCacheExpirationInterval similar to other settings.

Source/WebKit2: 

Hook up hasCachedPageExpired in InjectedBundle's BackForwardListItem.
* WebProcess/InjectedBundle/API/c/WKBundleBackForwardListItem.cpp:
(WKBundleBackForwardListItemHasCachedPageExpired):
* WebProcess/InjectedBundle/API/c/WKBundleBackForwardListItem.h:
* WebProcess/InjectedBundle/InjectedBundleBackForwardListItem.h:
(WebKit::InjectedBundleBackForwardListItem::hasCachedPageExpired):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145789 268f45cc-cd09-0410-ab3c-d52691b4dbfc