Change SkSL main() from (float x, float y) to (float2 p)

Change-Id: Id046199edd63535ef07e1dfa65fbc7c0f8cefd00
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/269371
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/gpu/effects/GrSkSLFP.cpp b/src/gpu/effects/GrSkSLFP.cpp
index 48d3b79..bd5a7cd 100644
--- a/src/gpu/effects/GrSkSLFP.cpp
+++ b/src/gpu/effects/GrSkSLFP.cpp
@@ -44,13 +44,8 @@
                             case SkSL::Compiler::FormatArg::Kind::kOutput:
                                 result += args.fOutputColor;
                                 break;
-                            case SkSL::Compiler::FormatArg::Kind::kCoordX:
+                            case SkSL::Compiler::FormatArg::Kind::kCoords:
                                 result += coordsName;
-                                result += ".x";
-                                break;
-                            case SkSL::Compiler::FormatArg::Kind::kCoordY:
-                                result += coordsName;
-                                result += ".y";
                                 break;
                             case SkSL::Compiler::FormatArg::Kind::kUniform:
                                 result += args.fUniformHandler->getUniformCStr(