Removed some dead code in the page cache
https://bugs.webkit.org/show_bug.cgi?id=111525

Reviewed by Alexey Proskuryakov.

Page cache autorelease doesn't exist anymore, so there's no need to keep
around these olds hacks.

../WebCore: 

* WebCore.exp.in:
* history/PageCache.cpp:
(WebCore::PageCache::PageCache):
(WebCore):
* history/PageCache.h:
(PageCache):
* page/Settings.cpp:
(WebCore::Settings::setUsesPageCache):
* platform/mac/MemoryPressureHandlerMac.mm:
(WebCore::MemoryPressureHandler::releaseMemory):
* platform/qt/QtTestSupport.cpp:
(WebKit::QtTestSupport::clearMemoryCaches):

../WebKit/blackberry: 

* Api/BlackBerryGlobal.cpp:
(BlackBerry::WebKit::clearMemoryCaches):
* Api/WebPage.cpp:
(BlackBerry::WebKit::WebPage::destroy):

../WebKit/efl: 

* ewk/ewk_settings.cpp:
(ewk_settings_memory_cache_clear):

../WebKit/mac: 

This fixes <rdar://problem/4886761> Fix bizarre WebWindowWatcher policy in WebHistoryItem.

* History/WebHistoryItem.mm:
(+[WebHistoryItem _releaseAllPendingPageCaches]):
* History/WebHistoryItemInternal.h:
* Misc/WebCoreStatistics.mm:
(+[WebCoreStatistics autoreleasedPageCount]):
* WebView/WebView.mm:
(-[WebView _commonInitializationWithFrameName:groupName:]):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144953 268f45cc-cd09-0410-ab3c-d52691b4dbfc