[WK2][EFL] WebView should own page position and scale factor
https://bugs.webkit.org/show_bug.cgi?id=111075

Reviewed by Andreas Kling.

View content position and content scale factor should belong to WebView
rather than to EwkView as it decreases EwkView usage inside EFL-agnostic
WebView and improves WebView encapsulation.

* UIProcess/API/C/efl/WKView.cpp:
(WKViewGetContentScaleFactor):
(WKViewSetContentScaleFactor):

    New WKView API was added to set and get content scale factor.
    The view content scale factor is not the same as page scale factor:
    it always applies to content but not necessarily applies to the page.
    The view content scale factor is calculated by viewport controller
    and applies immediately for painting in UI process. Page scale factor
    is updated later after the frame is rendered to accomplish the pending
    scale change.

(WKViewGetContentPosition):
(WKViewSetContentPosition):

    New WKView API was added to set and get content position.
    Content position is set in UI units.

* UIProcess/API/C/efl/WKView.h:
* UIProcess/API/efl/EwkView.cpp:
(EwkView::EwkView):
* UIProcess/API/efl/EwkView.h:
(EwkView):
* UIProcess/efl/PageViewportControllerClientEfl.cpp:
(WebKit::PageViewportControllerClientEfl::setViewportPosition):
(WebKit::PageViewportControllerClientEfl::setPageScaleFactor):
* UIProcess/efl/WebView.cpp:
(WebKit::WebView::WebView):
(WebKit::WebView::paintToCairoSurface):
(WebKit::WebView::transformToScene):
(WebKit::WebView::updateViewportSize):
(WebKit::WebView::pageDidRequestScroll):
* UIProcess/efl/WebView.h:
(WebKit::WebView::setContentScaleFactor):
(WebKit::WebView::contentScaleFactor):
(WebView):
(WebKit::WebView::setContentPosition):
(WebKit::WebView::contentPosition):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147741 268f45cc-cd09-0410-ab3c-d52691b4dbfc