Reviewed by Hyatt.

        Allow changing the background color WebCore draws under transparent page backgrounds.
        No automated way to test. All tests pass, no performance regression.

        * bridge/mac/WebCoreFrameBridge.h:
        * bridge/mac/WebCoreFrameBridge.mm:
        (-[WebCoreFrameBridge setBaseBackgroundColor:]):
        * page/FrameView.cpp:
        (WebCore::FrameViewPrivate::FrameViewPrivate):
        (WebCore::FrameView::baseBackgroundColor):
        (WebCore::FrameView::setBaseBackgroundColor):
        * page/FrameView.h:
        * rendering/RenderBox.cpp:
        (WebCore::RenderBox::paintBackgroundExtended):
        * rendering/RenderView.cpp:
        (WebCore::RenderView::paintBoxDecorations):

WebKit:

        Reviewed by Hyatt.

        WebView API to allow changing the background color that draws under transparent page backgrounds.

        * WebView/WebFrame.m:
        (-[WebFrame _makeDocumentView]):
        (-[WebFrame _updateBackground]):
        * WebView/WebFrameInternal.h:
        * WebView/WebFrameView.m:
        (-[WebFrameView drawRect:]):
        * WebView/WebView.m:
        (-[WebView setBackgroundColor:]):
        (-[WebView backgroundColor]):
        (-[WebView _commonInitializationWithFrameName:groupName:]):
        (-[WebView setDrawsBackground:]):
        * WebView/WebViewPrivate.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@16027 268f45cc-cd09-0410-ab3c-d52691b4dbfc