Drop unnecessary uses of targetStatistics.dataRecordsRemoved in ResourceLoadObserver

Drop unnecessary uses of targetStatistics.dataRecordsRemoved in ResourceLoadObserver
https://bugs.webkit.org/show_bug.cgi?id=174234

Reviewed by Brent Fulgham.

Drop unnecessary uses of targetStatistics.dataRecordsRemoved in ResourceLoadObserver. It is
always 0 since this member is only initialized later on, in the UIProcess.

* loader/ResourceLoadObserver.cpp:
(WebCore::ResourceLoadObserver::logFrameNavigation):
(WebCore::ResourceLoadObserver::logSubresourceLoading):
(WebCore::ResourceLoadObserver::logWebSocketLoading):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@219236 268f45cc-cd09-0410-ab3c-d52691b4dbfc