https://bugs.webkit.org/show_bug.cgi?id=110261
<rdar://problem/13196122>

Reviewed by Simon Fraser.

Remove RenderLayerCompositor::willMoveOffscreen/didMoveOnscreen.
Add RenderLayerCompositor::setIsInWindow, and pipe in-window changes through from Page::setIsInWindow.
Adjust a few Document functions that previously called RenderView::didMoveOnscreen/willMoveOffscreen to use setIsInWindow instead, since in-win$

* WebCore.exp.in: Export Page::setIsInWindow.
* dom/Document.cpp:
(WebCore::Document::attach): Use setIsInWindow instead of didMoveOnscreen.
(WebCore::Document::documentWillBecomeInactive): Use setIsInWindow instead of willMoveOffscreen.
(WebCore::Document::documentDidResumeFromPageCache): Use setIsInWindow instead of didMoveOnscreen.
* page/FrameView.cpp:
(WebCore::FrameView::didMoveOnscreen):
(WebCore::FrameView::willMoveOffscreen):
RenderView doesn't care about moving on/offscreen, just in-window state.
(WebCore::FrameView::setIsInWindow): Added. Forward isInWindow changes to our RenderView.
* page/FrameView.h:
(FrameView): Add setIsInWindow.
* page/Page.cpp:
(WebCore::Page::setIsInWindow): Added. Forward isInWindow changes to the Page's FrameViews.
* page/Page.h:
(Page): Add setIsInWindow.
(WebCore::Page::isInWindow):
* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::setIsInWindow): Added. Replace willMoveOffscreen/didMoveOnscreen with setIsInWindow,
since that's the only change we actually care about.
* rendering/RenderLayerCompositor.h:
(RenderLayerCompositor): Add setIsInWindow.
* rendering/RenderView.cpp:
(WebCore::RenderView::setIsInWindow): Added. Replace willMoveOffscreen/didMoveOnscreen with setIsInWindow,
since that's the only change RenderLayerCompositor actually cares about.
* rendering/RenderView.h:
(RenderView): Add setIsInWindow.

* WebView/WebView.mm:
(-[WebView viewWillMoveToWindow:]):
(-[WebView viewDidMoveToWindow]):
Use Page::setIsInWindow in addition to willMoveOffscreen/didMoveOnscreen.

* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::setIsInWindow):
Use Page::setIsInWindow in addition to willMoveOffscreen/didMoveOnscreen.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143428 268f45cc-cd09-0410-ab3c-d52691b4dbfc