Get <chrono> out of StdLibExtras.h

Get <chrono> out of StdLibExtras.h
https://bugs.webkit.org/show_bug.cgi?id=172744

Reviewed by Saam Barati.

Source/WebCore:

Only bring in <chrono> and namespace std::literals::chrono_literals when necessary.

* fileapi/FileReader.cpp:
* inspector/InspectorOverlay.cpp:
* loader/CrossOriginPreflightResultCache.cpp:
* loader/cache/CachedResource.cpp:
(WebCore::CachedResource::freshnessLifetime):
* page/ResourceUsageThread.cpp:
(WebCore::ResourceUsageThread::threadBody):
* page/cocoa/MemoryReleaseCocoa.mm:
(WebCore::jettisonExpensiveObjectsOnTopLevelNavigation):
* platform/network/CacheValidation.cpp:
(WebCore::computeFreshnessLifetimeForHTTPFamily):
* platform/network/CacheValidation.h:

Source/WebKit2:

Only bring in <chrono> and namespace std::literals::chrono_literals when necessary.

* NetworkProcess/cache/NetworkCache.cpp:
* NetworkProcess/cache/NetworkCacheFileSystem.h:
* NetworkProcess/cache/NetworkCacheSpeculativeLoadManager.cpp:
* NetworkProcess/cache/NetworkCacheStorage.cpp:
(WebKit::NetworkCache::computeRecordWorth):
* Shared/mac/RemoteLayerBackingStoreCollection.mm:
* WebProcess/Cookies/WebCookieManager.h:

Source/WTF:

We hates std::chrono. Don't include it everywhere to discourage use.

* wtf/StdLibExtras.h:

Tools:

* TestWebKitAPI/Tests/WTF/WorkQueue.cpp:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@217603 268f45cc-cd09-0410-ab3c-d52691b4dbfc