Move tessellation shader files into a subdirectory

Also renames GrStrokeShader -> GrStrokeTessellationShader.

Bug: skia:10419
Change-Id: I75b09f794ef86a4cd8c467a1fd61cc87fe68091b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/413756
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/tessellate/GrStrokeTessellateOp.h b/src/gpu/tessellate/GrStrokeTessellateOp.h
index da375c4..daf9d3d 100644
--- a/src/gpu/tessellate/GrStrokeTessellateOp.h
+++ b/src/gpu/tessellate/GrStrokeTessellateOp.h
@@ -11,18 +11,18 @@
 #include "include/core/SkStrokeRec.h"
 #include "src/gpu/ops/GrMeshDrawOp.h"
 #include "src/gpu/tessellate/GrStrokeTessellator.h"
-#include "src/gpu/tessellate/GrTessellationShader.h"
+#include "src/gpu/tessellate/shaders/GrTessellationShader.h"
 
 class GrRecordingContext;
 
 // Renders strokes by linearizing them into sorted "parametric" and "radial" edges. See
-// GrStrokeShader.
+// GrStrokeTessellationShader.
 class GrStrokeTessellateOp : public GrDrawOp {
 public:
     GrStrokeTessellateOp(GrAAType, const SkMatrix&, const SkPath&, const SkStrokeRec&, GrPaint&&);
 
 private:
-    using ShaderFlags = GrStrokeShader::ShaderFlags;
+    using ShaderFlags = GrStrokeTessellationShader::ShaderFlags;
     using PathStrokeList = GrStrokeTessellator::PathStrokeList;
     DEFINE_OP_CLASS_ID