Make skpaint->grpaint flow work for composing draws

include/gpu/GrColor.h

Index: include/gpu/GrColor.h
diff --git a/include/gpu/GrColor.h b/include/gpu/GrColor.h
index 7e2b3b263f08e2c71cc5106bf4c8be778c1c54f0..6b83237626ae590746757ac28ce22b9a5c22a3f8 100644
--- a/include/gpu/GrColor.h
+++ b/include/gpu/GrColor.h
@@ -17,8 +17,8 @@
 #include "SkUnPreMultiply.h"
 
 /**
- * GrColor is 4 bytes for R, G, B, A, in a specific order defined below. The components are stored
- * premultiplied.
+ * GrColor is 4 bytes for R, G, B, A, in a specific order defined below. Whether the color is
+ * premultiplied or not depends on the context in which it is being used.
  */
 typedef uint32_t GrColor;