Add an option to create unpremultiplied bitmaps.

include/core/SkColor.h

Index: include/core/SkColor.h
diff --git a/include/core/SkColor.h b/include/core/SkColor.h
index dafc59676d2fd3ea50fa1c131d5a65db3fcba107..76bdfd4850a69bcd365580958fcfe666a34bd9fd 100644
--- a/include/core/SkColor.h
+++ b/include/core/SkColor.h
@@ -145,6 +145,14 @@ static inline SkColor SkHSVToColor(const SkScalar hsv[3])
 */
 typedef uint32_t SkPMColor;
 
+/** Like SkPMColor, this is a 32 bit ARGB configuration dependent ordered color, but it is

[reed1, 2013/06/12 20:20:00]

On conservative side, lets not make this public (yet)

+    nonpremultiplied, like SkColor.
+*/
+typedef SkPMColor SkUnPMColor;
+
+// Convert an unmultiplied color to a premultiplied color.
+SkPMColor SkPreMultiplyUnPMColor(SkUnPMColor c);
+
 /** Return a SkPMColor value from unpremultiplied 8 bit component values
 */
 SK_API SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b);