Add SkPMColor4f support to SkSL

Convert GrConstColorProcessor to store SkPMColor4f

Bug: skia:
Change-Id: I6c505856653a02e576ae11fca59dc307545437f7
Reviewed-on: https://skia-review.googlesource.com/c/159152
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/sksl/SkSLParser.cpp b/src/sksl/SkSLParser.cpp
index 412a09e..91f2168 100644
--- a/src/sksl/SkSLParser.cpp
+++ b/src/sksl/SkSLParser.cpp
@@ -122,6 +122,7 @@
     TOKEN(TRACKED,                      "tracked");
     TOKEN(CTYPE,                        "ctype");
     TOKEN(GRCOLOR4F,                    "GrColor4f");
+    TOKEN(SKPMCOLOR4F,                  "SkPMColor4f");
     TOKEN(SKRECT,                       "SkRect");
     TOKEN(SKIRECT,                      "SkIRect");
     TOKEN(SKPMCOLOR,                    "SkPMColor");
@@ -730,6 +731,8 @@
             switch (found->second) {
                 case LayoutToken::GRCOLOR4F:
                     return Layout::CType::kGrColor4f;
+                case LayoutToken::SKPMCOLOR4F:
+                    return Layout::CType::kSkPMColor4f;
                 case LayoutToken::SKRECT:
                     return Layout::CType::kSkRect;
                 case LayoutToken::SKIRECT: