Rename GLRTFBOIDIs0 to WrapsSwapchainSurface and use for Metal.

This provides a way to indicate that a Metal RenderTarget, and in
particular a RenderTargetProxy, is framebufferOnly, so it can be
restricted to certain operations.

Bug: skia:9573
TBR: bsalomon@google.com
Change-Id: I733fae2fce402c375534889346255afe28a57944
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255783
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/gl/GrGLRenderTarget.cpp b/src/gpu/gl/GrGLRenderTarget.cpp
index 48aad47..b583191 100644
--- a/src/gpu/gl/GrGLRenderTarget.cpp
+++ b/src/gpu/gl/GrGLRenderTarget.cpp
@@ -47,7 +47,7 @@
 
 inline void GrGLRenderTarget::setFlags(const GrGLCaps& glCaps, const IDs& idDesc) {
     if (!idDesc.fRTFBOID) {
-        this->setGLRTFBOIDIs0();
+        this->setWrapsSwapchainSurface();
     }
 }