[EFL] Unreviewed build fix after r147251
https://bugs.webkit.org/show_bug.cgi?id=113631

Unreviewed build fix.

Add NETWORK_PROCESS guard.

Patch by Seokju Kwon <seokju.kwon@gmail.com> on 2013-03-29

* UIProcess/WebResourceCacheManagerProxy.cpp:
(WebKit::WebResourceCacheManagerProxy::clearCacheForAllOrigins):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147268 268f45cc-cd09-0410-ab3c-d52691b4dbfc