This reverts http://trac.webkit.org/changeset/101286
to fix Gentoo bug https://bugs.gentoo.org/show_bug.cgi?id=393471

Index: third_party/WebKit/Source/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp
===================================================================
--- third_party/WebKit/Source/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp	(revision 96970)
+++ third_party/WebKit/Source/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp	(revision 101286)
@@ -67,24 +67,6 @@
 
 #include <setjmp.h>
 
-#if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN)
-#define ASSUME_LITTLE_ENDIAN 0
-#else
-#define ASSUME_LITTLE_ENDIAN 1
-#endif
-
-#if defined(JCS_ALPHA_EXTENSIONS) && ASSUME_LITTLE_ENDIAN
-#define TURBO_JPEG_RGB_SWIZZLE
-#if USE(SKIA) && (!SK_R32_SHIFT && SK_G32_SHIFT == 8 && SK_B32_SHIFT == 16)
-inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_RGBA; }
-#else
-inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; }
-#endif
-inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == rgbOutputColorSpace(); }
-#else
-inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; }
-#endif
-
 namespace WebCore {
 
 struct decoder_error_mgr {
@@ -270,7 +252,7 @@
             case JCS_RGB:
             case JCS_YCbCr:
                 // libjpeg can convert GRAYSCALE and YCbCr image pixels to RGB.
-                m_info.out_color_space = rgbOutputColorSpace();
+                m_info.out_color_space = JCS_RGB;
                 break;
             case JCS_CMYK:
             case JCS_YCCK:
@@ -525,19 +507,6 @@
     }
 
     jpeg_decompress_struct* info = m_reader->info();
-
-#if !ENABLE(IMAGE_DECODER_DOWN_SAMPLING) && defined(TURBO_JPEG_RGB_SWIZZLE)
-    if (turboSwizzled(info->out_color_space)) {
-         ASSERT(!m_scaled);
-         while (info->output_scanline < info->output_height) {
-             unsigned char* row = reinterpret_cast<unsigned char*>(buffer.getAddr(0, info->output_scanline));
-             if (jpeg_read_scanlines(info, &row, 1) != 1)
-                  return false;
-         }
-         return true;
-     }
-#endif
-
     JSAMPARRAY samples = m_reader->samples();
 
     while (info->output_scanline < info->output_height) {