Reviewed by Eric Seidel.

        https://bugs.webkit.org/show_bug.cgi?id=26460 part three
        Make BMPImageReader a standalone class that is used by ICOImageDecoder
        and BMPImageDecoder to decode individual BMPs within a file.  These
        decoders now inherit directly from ImageDecoder.
        
        This also makes these decoders decode on-demand in isSizeAvailable() and
        frameBufferAtIndex(), like the other decoders, instead of when setData()
        is called, like before.  This should provide a speedup on pages
        containing BMPs that aren't immediately onscreen.

        * platform/image-decoders/bmp/BMPImageDecoder.cpp:
        (WebCore::BMPImageDecoder::BMPImageDecoder):
        (WebCore::BMPImageDecoder::setData):
        (WebCore::BMPImageDecoder::isSizeAvailable):
        (WebCore::BMPImageDecoder::frameBufferAtIndex):
        (WebCore::BMPImageDecoder::decodeWithCheckForDataEnded):
        (WebCore::BMPImageDecoder::decode):
        (WebCore::BMPImageDecoder::processFileHeader):
        * platform/image-decoders/bmp/BMPImageDecoder.h:
        (WebCore::BMPImageDecoder::readUint32):
        * platform/image-decoders/bmp/BMPImageReader.cpp:
        (WebCore::BMPImageReader::BMPImageReader):
        (WebCore::BMPImageReader::decodeBMP):
        (WebCore::BMPImageReader::readInfoHeaderSize):
        (WebCore::BMPImageReader::processInfoHeader):
        (WebCore::BMPImageReader::readInfoHeader):
        (WebCore::BMPImageReader::processBitmasks):
        (WebCore::BMPImageReader::processColorTable):
        (WebCore::BMPImageReader::processRLEData):
        (WebCore::BMPImageReader::processNonRLEData):
        (WebCore::BMPImageReader::setFailed):
        * platform/image-decoders/bmp/BMPImageReader.h:
        (WebCore::BMPImageReader::readUint16):
        (WebCore::BMPImageReader::readUint32):
        (WebCore::BMPImageReader::setBuffer):
        (WebCore::BMPImageReader::setData):
        (WebCore::BMPImageReader::):
        (WebCore::BMPImageReader::pastEndOfImage):
        (WebCore::BMPImageReader::readCurrentPixel):
        (WebCore::BMPImageReader::setRGBA):
        * platform/image-decoders/ico/ICOImageDecoder.cpp:
        (WebCore::ICOImageDecoder::ICOImageDecoder):
        (WebCore::ICOImageDecoder::setData):
        (WebCore::ICOImageDecoder::isSizeAvailable):
        (WebCore::ICOImageDecoder::size):
        (WebCore::ICOImageDecoder::frameBufferAtIndex):
        (WebCore::ICOImageDecoder::decodeWithCheckForDataEnded):
        (WebCore::ICOImageDecoder::decode):
        (WebCore::ICOImageDecoder::processDirectory):
        (WebCore::ICOImageDecoder::processDirectoryEntries):
        (WebCore::ICOImageDecoder::readDirectoryEntry):
        (WebCore::ICOImageDecoder::processImageType):
        * platform/image-decoders/ico/ICOImageDecoder.h:
        (WebCore::ICOImageDecoder::readUint16):
        (WebCore::ICOImageDecoder::readUint32):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@44874 268f45cc-cd09-0410-ab3c-d52691b4dbfc