Reviewed by Kenneth Russell.

        [chromium] Allow turning off multisampling through web preference settings
        https://bugs.webkit.org/show_bug.cgi?id=54321

        * public/WebSettings.h: Add a flag for multisampling setting.
        * src/WebSettingsImpl.cpp: Ditto.
        (WebKit::WebSettingsImpl::setOpenGLMultisamplingEnabled):
        * src/WebSettingsImpl.h: Ditto.
2011-02-11  Zhenyao Mo  <zmo@google.com>

        Reviewed by Kenneth Russell.

        [chromium] Allow turning off multisampling through web preference settings
        https://bugs.webkit.org/show_bug.cgi?id=54321

        * html/canvas/WebGLRenderingContext.cpp:
        (WebCore::WebGLRenderingContext::create): Disable multisampling in WebGL if web reference says so.
        * page/Settings.cpp: Add a flag for multisampling preference.
        (WebCore::Settings::Settings):
        (WebCore::Settings::setOpenGLMultisamplingEnabled):
        * page/Settings.h: Ditto.
        (WebCore::Settings::openGLMultisamplingEnabled):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@78419 268f45cc-cd09-0410-ab3c-d52691b4dbfc