Reviewed by Sam Weinig.

        - WebCore part of https://bugs.webkit.org/show_bug.cgi?id=21736
          Long-dead decoded image data make up for most of the object cache's memory use over time

        Add a cache setting for how long decoded image data should be allowed to
        persist in memory after the image has died. By default, this is set to
        0, which means "forever".

        * loader/Cache.cpp:
        (WebCore::Cache::Cache): Initialize m_deadDecodedDataDeletionInterval.
        * loader/Cache.h:
        (WebCore::Cache::setDeadDecodedDataDeletionInterval): Added a setter.
        (WebCore::Cache::deadDecodedDataDeletionInterval): Added a getter.
        * loader/CachedImage.cpp:
        (WebCore::CachedImage::CachedImage): Initialize the decoded data
        deletion timer.
        (WebCore::CachedImage::decodedDataDeletionTimerFired): Added. Destroys
        the decoded image data.
        (WebCore::CachedImage::addClient): Stop the timer if it is active.
        (WebCore::CachedImage::allClientsRemoved): Start the decoded data
        deletion timer.
        * loader/CachedImage.h:

WebKit/mac:

        Reviewed by Sam Weinig.

        - WebKit/mac part of https://bugs.webkit.org/show_bug.cgi?id=21736
          Long-dead decoded image data make up for most of the object cache's memory use over time

        * WebView/WebView.mm:
        (+[WebView _setCacheModel:]): In the primary web browser model, set the
        cache's dead decoded data deletion interval to 60 seconds.

WebKit/win:

2008-10-18  Dan Bernstein  <mitz@apple.com>

        Reviewed by Sam Weinig.

        - WebKit/win part of https://bugs.webkit.org/show_bug.cgi?id=21736
          Long-dead decoded image data make up for most of the object cache's memory use over time

        * WebView.cpp:
        (WebView::setCacheModel): In the primary web browser model,
        set the cache's dead decoded data deletion interval to 60 seconds.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@37689 268f45cc-cd09-0410-ab3c-d52691b4dbfc