Mark existing image filter entry points that will be going away with Deprecated

gm/imagefiltersbase.cpp

Index: gm/imagefiltersbase.cpp
diff --git a/gm/imagefiltersbase.cpp b/gm/imagefiltersbase.cpp
index fbe4681da4276af5aa3a9616649dda78f4e033c1..a55328a999fd2489e9c463f0e03a2531ff8a6380 100644
--- a/gm/imagefiltersbase.cpp
+++ b/gm/imagefiltersbase.cpp
@@ -34,8 +34,8 @@ public:
 protected:
     FailImageFilter() : INHERITED(0, nullptr) {}
 
-    bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
-                       SkBitmap* result, SkIPoint* offset) const override {
+    bool onFilterImageDeprecated(Proxy*, const SkBitmap& src, const Context&,
+                                 SkBitmap* result, SkIPoint* offset) const override {
         return false;
     }
 
@@ -76,8 +76,8 @@ public:
 protected:
     IdentityImageFilter(SkImageFilter* input) : INHERITED(1, &input) {}
 
-    bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
-                       SkBitmap* result, SkIPoint* offset) const override {
+    bool onFilterImageDeprecated(Proxy*, const SkBitmap& src, const Context&,
+                                 SkBitmap* result, SkIPoint* offset) const override {
         *result = src;
         offset->set(0, 0);
         return true;