Coordinated Graphics: Make CoordinatedGraphicsScene not know contents size.

Coordinated Graphics: Make CoordinatedGraphicsScene not know contents size.
https://bugs.webkit.org/show_bug.cgi?id=108922

Source/WebCore:

Patch by Huang Dongsung <luxtella@company100.net> on 2013-02-11
Reviewed by Noam Rosenthal.

Currently, CoordinatedGraphicsScene has two methods to know contents
size: setContentsSize() and setVisibleContentsRect(). Contents size is
used when adjusting a scroll position, but adjustment is not needed
because EFL and Qt platform code (currently PageViewportController)
already adjusts a scroll position, and it is natural for each platform
to be in charge of adjusting. So this patch makes CoordinatedGraphicsScene
not know contents size.

In addition, now DrawingAreaProxy::coordinatedLayerTreeHostProxy() is only used
to get CoordinatedGraphicsScene.

This patch can only be tested manually since there is no automated
testing facilities for in-motion touch.
Test: ManualTests/fixed-position.html
      ManualTests/nested-fixed-position.html

* platform/graphics/texmap/TextureMapperLayer.cpp:
(WebCore::TextureMapperLayer::setScrollPositionDeltaIfNeeded):
* platform/graphics/texmap/coordinated/CoordinatedGraphicsScene.cpp:
(WebCore::CoordinatedGraphicsScene::setScrollPosition):
(WebCore::CoordinatedGraphicsScene::adjustPositionForFixedLayers):
* platform/graphics/texmap/coordinated/CoordinatedGraphicsScene.h:
(CoordinatedGraphicsScene):

Source/WebKit2:

Patch by Huang Dongsung <luxtella@company100.net> on 2013-02-11
Reviewed by Noam Rosenthal.
Signed off for WebKit2 by Benjamin Poulain.

Currently, CoordinatedGraphicsScene has two methods to know contents
size: setContentsSize() and setVisibleContentsRect(). Contents size is
used when adjusting a scroll position, but adjustment is not needed
because EFL and Qt platform code (currently PageViewportController)
already adjusts a scroll position, and it is natural for each platform
to be in charge of adjusting. So this patch makes CoordinatedGraphicsScene
not know contents size.

In addition, now DrawingAreaProxy::coordinatedLayerTreeHostProxy() is only used
to get CoordinatedGraphicsScene.

* UIProcess/API/qt/qquickwebpage.cpp:
(QQuickWebPagePrivate::updateSize):
* UIProcess/API/qt/raw/qrawwebview.cpp:
(QRawWebView::setSize):
* UIProcess/CoordinatedGraphics/CoordinatedLayerTreeHostProxy.cpp:
(WebKit::CoordinatedLayerTreeHostProxy::setVisibleContentsRect):
* UIProcess/CoordinatedGraphics/CoordinatedLayerTreeHostProxy.h:
(CoordinatedLayerTreeHostProxy):
* UIProcess/efl/PageClientLegacyImpl.cpp:
(WebKit::PageClientLegacyImpl::didChangeContentsSize):
* UIProcess/efl/PageViewportControllerClientEfl.cpp:
(WebKit::PageViewportControllerClientEfl::didChangeContentsSize):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@142579 268f45cc-cd09-0410-ab3c-d52691b4dbfc