Add Gr*Proxy classes

src/effects/SkMorphologyImageFilter.cpp

Index: src/effects/SkMorphologyImageFilter.cpp
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index 2a0f078c053fd6ed0cc13577668090b7415a6c1c..121a7fdc013a5eea116c629e9e99c20a1a71e045 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -487,7 +487,7 @@ static sk_sp<SkSpecialImage> apply_morphology(GrContext* context,
     SkASSERT(radius.width() > 0 || radius.height() > 0);
 
     if (radius.fWidth > 0) {
-        sk_sp<GrDrawContext> dstDrawContext(context->newDrawContext(GrContext::kLoose_BackingFit,
+        sk_sp<GrDrawContext> dstDrawContext(context->newDrawContext(SkBackingFit::kApprox,
                                                                     rect.width(), rect.height(),
                                                                     kSkia8888_GrPixelConfig));
         if (!dstDrawContext) {
@@ -508,7 +508,7 @@ static sk_sp<SkSpecialImage> apply_morphology(GrContext* context,
         srcRect = dstRect;
     }
     if (radius.fHeight > 0) {
-        sk_sp<GrDrawContext> dstDrawContext(context->newDrawContext(GrContext::kLoose_BackingFit,
+        sk_sp<GrDrawContext> dstDrawContext(context->newDrawContext(SkBackingFit::kApprox,
                                                                     rect.width(), rect.height(),
                                                                     kSkia8888_GrPixelConfig));
         if (!dstDrawContext) {