[WK2][EFL] Add WKView methods related to background drawing
https://bugs.webkit.org/show_bug.cgi?id=109159

Reviewed by Anders Carlsson.

* UIProcess/API/C/efl/WKView.cpp:
(WKViewSetDrawsBackground):
(WKViewGetDrawsBackground):
(WKViewSetDrawsTransparentBackground):
(WKViewGetDrawsTransparentBackground):
 * UIProcess/efl/WebView.cpp:
(WebKit::WebView::setDrawsBackground):
(WebKit):
(WebKit::WebView::drawsBackground):
(WebKit::WebView::setDrawsTransparentBackground):
(WebKit::WebView::drawsTransparentBackground):
* UIProcess/efl/WebView.h:
(WebView):
       * UIProcess/API/C/efl/WKView.h:

    New methods added

* UIProcess/API/efl/EwkView.cpp:
(EwkView::EwkView):
(EwkView::displayTimerFired):
(EwkView::handleEvasObjectColorSet):
* UIProcess/API/efl/EwkView.h:
(EwkView):
* UIProcess/API/efl/ewk_view.cpp:
(ewk_view_draws_page_background_set):

    Remove the unneeded m_setDrawsBackground and replace
    it with the WKView setting.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@142157 268f45cc-cd09-0410-ab3c-d52691b4dbfc