Re-re-land "added GrSkSLFP and converted DitherEffect to use it"

This reverts commit 6c48e4d11ce80fa5cfef56e13b2d5847fe94a7cc.

Bug: skia:
Change-Id: I7ee78990fc30eec545d1856e59eb6e0573089426
Reviewed-on: https://skia-review.googlesource.com/144348
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/sksl/ir/SkSLSwizzle.h b/src/sksl/ir/SkSLSwizzle.h
index e713a323b3..412ed903bb 100644
--- a/src/sksl/ir/SkSLSwizzle.h
+++ b/src/sksl/ir/SkSLSwizzle.h
@@ -127,6 +127,10 @@ struct Swizzle : public Expression {
         return fBase->hasSideEffects();
     }
 
+    std::unique_ptr<Expression> clone() const override {
+        return std::unique_ptr<Expression>(new Swizzle(fType, fBase->clone(), fComponents));
+    }
+
     String description() const override {
         String result = fBase->description() + ".";
         for (int x : fComponents) {
@@ -139,6 +143,16 @@ struct Swizzle : public Expression {
     const std::vector<int> fComponents;
 
     typedef Expression INHERITED;
+
+private:
+    Swizzle(const Type& type, std::unique_ptr<Expression> base, std::vector<int> components)
+    : INHERITED(base->fOffset, kSwizzle_Kind, type)
+    , fBase(std::move(base))
+    , fComponents(std::move(components)) {
+        SkASSERT(fComponents.size() >= 1 && fComponents.size() <= 4);
+    }
+
+
 };
 
 } // namespace