Revert "Revert "added support for sk_Dimensions to SkSL""

This reverts commit e6ab998bc2e675ab0a426ec9434be887e5527ab3.

Bug: skia:
Change-Id: I19451f924d514dadac9d2c326bcc8404a1b501e9
Reviewed-on: https://skia-review.googlesource.com/149239
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/sksl/SkSLCPPCodeGenerator.h b/src/sksl/SkSLCPPCodeGenerator.h
index 014f917..39255d6 100644
--- a/src/sksl/SkSLCPPCodeGenerator.h
+++ b/src/sksl/SkSLCPPCodeGenerator.h
@@ -68,6 +68,8 @@
 
     void writeVarInitializer(const Variable& var, const Expression& value) override;
 
+    void writeInputVars() override;
+
     void writePrivateVars();
 
     void writePrivateVarValues();