Reviewed by Simon Fraser.

        Use the Accelerate vImage vectorized (un)premultiplyImageData functions for ImageBufferCG

        https://bugs.webkit.org/show_bug.cgi?id=53134

        * wtf/Platform.h: Added in WTF flag for using the Accelerate framework
2011-03-29  Matthew Delaney  <mdelaney@apple.com>

        Reviewed by Simon Fraser.

        Use the Accelerate vImage vectorized (un)premultiplyImageData functions for ImageBufferCG

        https://bugs.webkit.org/show_bug.cgi?id=53134

        Test: fast/canvas/getPutImageDataPairTest.html

        * platform/graphics/cg/ImageBufferCG.cpp:
2011-03-25  Matthew Delaney  <mdelaney@apple.com>

        Reviewed by Simon Fraser.

        Use Accelerate vImage vectorized (un)premultiplyImageData functions for ImageBufferCG.cpp
        https://bugs.webkit.org/show_bug.cgi?id=53134

        * fast/canvas/canvas-getImageData-expected.txt: Resetting expected results for this test due to test change.
        * fast/canvas/canvas-getImageData.html: Removed the section of this test that incorrectly assumes the 
          rounding behavior of initial inputed data.
        * fast/canvas/getPutImageDataPairTest-expected.txt: Added.
        * fast/canvas/getPutImageDataPairTest.html: A new test to make sure that a batch of paired putImageData(getImageData)
          calls doesn't accumulate any error per the spec.
        * fast/canvas/rgba-parsing-expected.txt: Reset the results for this test since the initial rgba rounding values are
          now different. Note: the spec does not define how they *should* be rounded, so having them there is basically just
          for bookkeeping to know when our rounding behavior changes since it could be early warning of related real issues.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@82516 268f45cc-cd09-0410-ab3c-d52691b4dbfc