added support for PLS path rendering

src/gpu/gl/builders/GrGLProgramBuilder.h

Index: src/gpu/gl/builders/GrGLProgramBuilder.h
diff --git a/src/gpu/gl/builders/GrGLProgramBuilder.h b/src/gpu/gl/builders/GrGLProgramBuilder.h
index cbec5a9863539b125b75560ed6de8e5f55647782..fd439540e530765e99b245e56783fb061ab9e595 100644
--- a/src/gpu/gl/builders/GrGLProgramBuilder.h
+++ b/src/gpu/gl/builders/GrGLProgramBuilder.h
@@ -88,10 +88,11 @@ private:
     void emitAndInstallProc(const GrPrimitiveProcessor&,
                             const char* outColor,
                             const char* outCoverage);
-    void emitAndInstallXferProc(const GrXferProcessor&,
-                                const GrGLSLExpr4& colorIn,
-                                const GrGLSLExpr4& coverageIn,
-                                bool ignoresCoverage);
+    virtual void emitAndInstallXferProc(const GrXferProcessor&,
+                                        const GrGLSLExpr4& colorIn,
+                                        const GrGLSLExpr4& coverageIn,
+                                        bool ignoresCoverage,
+                                        GrPixelLocalStorageState plsState);
 
     void verify(const GrPrimitiveProcessor&);
     void verify(const GrXferProcessor&);