Add support for converting Colors to linear RGB; Fix relevant filters

Source/platform/graphics/ColorSpace.h

Index: Source/platform/graphics/ColorSpace.h
diff --git a/Source/platform/graphics/ColorSpace.h b/Source/platform/graphics/ColorSpace.h
index 06918f7ff1f9217d43aca2426ab69fdd4597a244..7a895e10e0f3739bb0875fa5c182dcc74f18900e 100644
--- a/Source/platform/graphics/ColorSpace.h
+++ b/Source/platform/graphics/ColorSpace.h
@@ -27,6 +27,7 @@
 #define ColorSpace_h
 
 #include "platform/PlatformExport.h"
+#include "wtf/Vector.h"
 
 namespace WebCore {
 
@@ -36,6 +37,15 @@ enum ColorSpace {
     ColorSpaceLinearRGB
 };
 
+// Get a reference to a 8-bit lookup table that will convert color components
+// in the device RGB space to linear RGB.
+const Vector<uint8_t>& getLinearRgbLUT();

[f(malita), 2014/01/22 15:09:32]

Now that these have external visibility, they should probably be encapsulated
somehow.

Time for a ColorSpace class maybe? It would be home for:

* ColorSpaceType enum
* static get*LUT methods
* static createColorSpaceFilter() (to be relocated from ImageBuffer, where it
doesn't really belong)
* static convertColor() (to be relocated from Color)

+
+// Get a reference to a 8-bit lookup table that will convert color components
+// in the linear RGB space to device RGB (see above). I.e., the inverse of the
+// above. (Note however that a round-trip is not lossless.)
+const Vector<uint8_t>& getDeviceRgbLUT();
+
 } // namespace WebCore
 
 #endif // ColorSpace_h