Let {Argb,Cmyk}Decode return tuples

Change-Id: Ic4e766d9417f9a9ece5f9e4269d0f96e1e91639b
Reviewed-on: https://pdfium-review.googlesource.com/4392
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/javascript/Field.cpp b/fpdfsdk/javascript/Field.cpp
index c7dc260..8e4b465 100644
--- a/fpdfsdk/javascript/Field.cpp
+++ b/fpdfsdk/javascript/Field.cpp
@@ -2381,7 +2381,7 @@
   int32_t r;
   int32_t g;
   int32_t b;
-  ArgbDecode(color, a, r, g, b);
+  std::tie(a, r, g, b) = ArgbDecode(color);
 
   CPWL_Color crRet =
       CPWL_Color(COLORTYPE_RGB, r / 255.0f, g / 255.0f, b / 255.0f);