converted GrMagnifierEffect to SkSL

Bug: skia:
Change-Id: I6dc14ac66d5b911117e71fa23fef49a897082781
Reviewed-on: https://skia-review.googlesource.com/71342
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/effects/GrRectBlurEffect.cpp b/src/gpu/effects/GrRectBlurEffect.cpp
index 573c131..e656d84 100644
--- a/src/gpu/effects/GrRectBlurEffect.cpp
+++ b/src/gpu/effects/GrRectBlurEffect.cpp
@@ -13,6 +13,7 @@
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramBuilder.h"
+#include "GrTexture.h"
 #include "SkSLCPP.h"
 #include "SkSLUtil.h"
 class GrGLSLRectBlurEffect : public GrGLSLFragmentProcessor {
@@ -113,7 +114,8 @@
         (void)rect;
         auto sigma = _outer.sigma();
         (void)sigma;
-        UniformHandle& blurProfile = fBlurProfileVar;
+        GrSurfaceProxy& blurProfileProxy = *_outer.textureSampler(0).proxy();
+        GrTexture& blurProfile = *blurProfileProxy.priv().peekTexture();
         (void)blurProfile;
         UniformHandle& proxyRectHalf = fProxyRectHalfVar;
         (void)proxyRectHalf;