[cogl] Make the blend string error domain public

The error domain and codes must present in a publicly installed header
otherwise they won't be usable to match a GError.

cogl-types.h

@@ -295,6 +295,17 @@ typedef enum {
   COGL_FOG_MODE_EXPONENTIAL_SQUARED
 } CoglFogMode;
 
+#define COGL_BLEND_STRING_ERROR (cogl_blend_string_error_quark ())
+
+typedef enum { /*< prefix=COGL_BLEND_STRING_ERROR >*/
+  COGL_BLEND_STRING_ERROR_PARSE_ERROR,
+  COGL_BLEND_STRING_ERROR_ARGUMENT_PARSE_ERROR,
+  COGL_BLEND_STRING_ERROR_INVALID_ERROR,
+  COGL_BLEND_STRING_ERROR_GPU_UNSUPPORTED_ERROR
+} CoglBlendStringError;
+
+GQuark cogl_blend_string_error_quark (void);
+
 G_END_DECLS
 
 #endif /* __COGL_TYPES_H__ */

common/cogl-blend-string.c

@@ -122,7 +122,7 @@ static CoglBlendStringFunctionInfo blend_functions[] = {
 #undef DEFINE_FUNCTION
 
 GQuark
-_cogl_blend_string_error_quark (void)
+cogl_blend_string_error_quark (void)
 {
   return g_quark_from_static_string ("cogl-blend-string-error-quark");
 }

common/cogl-blend-string.h

@@ -36,16 +36,6 @@ typedef enum _CoglBlendStringContext
   COGL_BLEND_STRING_CONTEXT_TEXTURE_COMBINE
 } CoglBlendStringContext;
 
-#define COGL_BLEND_STRING_ERROR _cogl_blend_string_error_quark ()
-
-typedef enum _CoglBlendStringError
-{
-  COGL_BLEND_STRING_ERROR_PARSE_ERROR,
-  COGL_BLEND_STRING_ERROR_ARGUMENT_PARSE_ERROR,
-  COGL_BLEND_STRING_ERROR_INVALID_ERROR,
-  COGL_BLEND_STRING_ERROR_GPU_UNSUPPORTED_ERROR
-} CoglBlendStringError;
-
 /* NB: debug stringify code will get upset if these
  * are re-ordered */
 typedef enum _CoglBlendStringChannelMask
@@ -144,8 +134,5 @@ _cogl_blend_string_split_rgba_statement (CoglBlendStringStatement *statement,
                                          CoglBlendStringStatement *rgb,
                                          CoglBlendStringStatement *a);
 
-GQuark
-_cogl_blend_string_error_quark (void);
-
 #endif /* COGL_BLEND_STRING_H */