Added testRunner.setPrinting.
https://bugs.webkit.org/show_bug.cgi?id=42693
rdar://problem/8213845

Patch by Alex Christensen <achristensen@apple.com> on 2013-05-13
Reviewed by Darin Adler.

Source/WebKit2:

* WebProcess/InjectedBundle/API/c/WKBundlePage.cpp:
(WKBundlePageCopyRenderTreeExternalRepresentationForPrinting): Added.
* WebProcess/InjectedBundle/API/c/WKBundlePagePrivate.h:
Added WKBundlePageCopyRenderTreeExternalRepresentationForPrinting declaration.
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::renderTreeExternalRepresentationForPrinting): Added.
* WebProcess/WebPage/WebPage.h:
Added renderTreeExternalRepresentationForPrinting declaration.

Tools:

* WebKitTestRunner/InjectedBundle/Bindings/TestRunner.idl:
Added setPrinting JavaScript function.
* WebKitTestRunner/InjectedBundle/InjectedBundlePage.cpp:
(WTR::InjectedBundlePage::dump):
Dump the external representation for printing if setPrinting has been called.
* WebKitTestRunner/InjectedBundle/TestRunner.h:
(WTR::TestRunner::isPrinting): Added.
(WTR::TestRunner::setPrinting): Added.
Added and initialized m_isPrinting member boolean.

LayoutTests:

* platform/wk2/TestExpectations:
Unskipped printing tests.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150046 268f45cc-cd09-0410-ab3c-d52691b4dbfc