[chromium] remove methods from the WebTestRunner interface that are only used by WebTestProxyBase
https://bugs.webkit.org/show_bug.cgi?id=108926

Reviewed by Adam Barth.

* DumpRenderTree/chromium/TestRunner/public/WebTestRunner.h:
(WebKit):
(WebTestRunner):
* DumpRenderTree/chromium/TestRunner/src/TestRunner.h:
(TestRunner):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141899 268f45cc-cd09-0410-ab3c-d52691b4dbfc