Update fully lazy proxy checks to look for negative w/h

Bug: chromium:1000004
Change-Id: I73fcd98682853a057d8ee6a1c224bf43587f906a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240691
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrSurfaceProxy.h b/src/gpu/GrSurfaceProxy.h
index cee5931..ad29e0a 100644
--- a/src/gpu/GrSurfaceProxy.h
+++ b/src/gpu/GrSurfaceProxy.h
@@ -102,8 +102,8 @@
     bool isLazy() const { return !this->isInstantiated() && SkToBool(fLazyInstantiateCallback); }
 
     bool isFullyLazy() const {
-        bool result = fHeight <= 0;
-        SkASSERT(result == (fWidth <= 0));
+        bool result = fHeight < 0;
+        SkASSERT(result == (fWidth < 0));
         SkASSERT(!result || this->isLazy());
         return result;
     }