[Qt][EFL][WK2] Remove redundant device pixel ratio adjustment from PageViewportController
https://bugs.webkit.org/show_bug.cgi?id=106355

Reviewed by Kenneth Rohde Christiansen.

Since r137597 Qt uses the device pixel ratio of the underlying
platform window as the device pixel ratio in WebCore.
The tiles are rendered with the effective scale (scale adjusted with
the device scale factor) and the projection matrix is also adjusted
with the device pixel ratio when painting.
As a result we can follow the same approach as QtQuick and all the
coordinates in PageViewportController need to be in device independent
pixels (UI pixels) thus we do no longer need to adjust with the device
pixel ratio when calculating the viewport attributes.
This simplifies the logic significantly and increases robustness,
but does not allow to set a custom device pixel ratio different from
the factor of the underlying platform (eg. for testing purposes).
This patch is conceptually a follow-up of r137597 and fixes layout
and canvas size on retina display.

* UIProcess/PageViewportController.cpp:
(WebKit::PageViewportController::PageViewportController):
(WebKit::PageViewportController::innerBoundedViewportScale):
(WebKit::PageViewportController::outerBoundedViewportScale):
(WebKit::PageViewportController::pixelAlignedFloatPoint):
(WebKit::PageViewportController::boundContentsPosition):
(WebKit::PageViewportController::didRenderFrame):
(WebKit::PageViewportController::pageTransitionViewportReady):
(WebKit::PageViewportController::didChangeContentsVisibility):
(WebKit::PageViewportController::syncVisibleContents):
(WebKit::PageViewportController::visibleContentsSize):
(WebKit::PageViewportController::applyScaleAfterRenderingContents):
(WebKit::PageViewportController::updateMinimumScaleToFit):
* UIProcess/PageViewportController.h:
(WebKit::PageViewportController::currentContentsScale):
(PageViewportController):
* UIProcess/efl/PageViewportControllerClientEfl.cpp:
(WebKit::PageViewportControllerClientEfl::updateViewportSize):
Adjust the viewport size with the device pixel ratio to keep previous
behaviour.
* UIProcess/qt/PageViewportControllerClientQt.cpp:
(WebKit::PageViewportControllerClientQt::focusEditableArea):
(WebKit::PageViewportControllerClientQt::zoomToAreaGestureEnded):
* UIProcess/qt/QtWebPageSGNode.cpp:
(WebKit::ContentsSGNode::clipRect):
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::sendViewportAttributesChanged):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@139189 268f45cc-cd09-0410-ab3c-d52691b4dbfc