Use presence of a content key as non-scratch indicator

src/gpu/GrResourceCache2.cpp

Index: src/gpu/GrResourceCache2.cpp
diff --git a/src/gpu/GrResourceCache2.cpp b/src/gpu/GrResourceCache2.cpp
index 85e66a7642ad45ea373eded4ef9c878fcb4ea181..5144c59eef44f38ca5da81bb90caba0d7817caa1 100644
--- a/src/gpu/GrResourceCache2.cpp
+++ b/src/gpu/GrResourceCache2.cpp
@@ -67,15 +67,15 @@ public:
             // either by drawing code or for pending io operations.
             // This will be removed when flush no longer creates resources.
             return resource->reffedOnlyByCache() && !resource->internalHasPendingIO() &&
-                   GrGpuResource::kYes_IsScratch == resource->fIsScratch;
+                   resource->isScratch();
         } else {
             // Because duties are currently shared between GrResourceCache and GrResourceCache2, the
             // current interpretation of this rule is that only GrResourceCache has a ref but that
             // it has been marked as a scratch resource.
-            return resource->reffedOnlyByCache() &&
-                GrGpuResource::kYes_IsScratch == resource->fIsScratch;
+            return resource->reffedOnlyByCache() && resource->isScratch();
         }
     }
+
 private:
     bool fFlushing;
 };