[Qt] Port DRT to use TestRunner::dumpAsText()
https://bugs.webkit.org/show_bug.cgi?id=112260

Reviewed by Benjamin Poulain.

* DumpRenderTree/qt/DumpRenderTreeQt.cpp:
(WebCore::DumpRenderTree::open):
(WebCore::methodNameStringForFailedTest):
    Change parameter from type TestRunnerQt* to TestRunner*.
(WebCore::DumpRenderTree::dump):
    TestRunnerQt::shouldDumpPixels() always returned true in our case.
    Instead we should rely on TestRunner::generatePixelResults().
* DumpRenderTree/qt/TestRunnerQt.cpp:
(TestRunnerQt::reset):
* DumpRenderTree/qt/TestRunnerQt.h:
(TestRunnerQt):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145800 268f45cc-cd09-0410-ab3c-d52691b4dbfc