Reviewed by Dan Bernstein.

        Issues with iframes and plugins when the WebView is scaled.
        <rdar://problem/6213380>

        When _scaleWebView has been called on a WebView, iframes
        in WebKit1 render and hit-test incorrectly, and plug-ins don't scale up.
        This is caused by AppKit NSViews not playing nicely with the scale
        applied through style.

        Work around most of these issues by adjusting the bounds size
        of widgets to allow iframe contents to paint with the correct scale,
        and fix various places in the code where we relied on coordinate
        transforms via NSViews (which ignore CSS transforms).

        * WebCore.exp.in:
        * platform/Widget.cpp:
        (WebCore::Widget::setBoundsSize):
        * platform/Widget.h:
        * platform/mac/WidgetMac.mm:
        (WebCore::Widget::setBoundsSize):
        (WebCore::Widget::paint):
        * rendering/RenderLayerCompositor.cpp:
        (WebCore::RenderLayerCompositor::shouldPropagateCompositingToEnclosingIFrame):
        * rendering/RenderWidget.cpp:
        (WebCore::RenderWidget::setWidgetGeometry):
        (WebCore::RenderWidget::setWidget):
        (WebCore::RenderWidget::updateWidgetPosition):
        * rendering/RenderWidget.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@75897 268f45cc-cd09-0410-ab3c-d52691b4dbfc