Alter GrSurface/GrSurfaceProxy flags to prepare for GrTexture/GrTextureProxy -specific flags

This CL:
  moves GrRenderTarget::fFlags to GrSurface::fSurfaceFlags
  adds a GrInternalSurfaceFlags type and uses it for GrSurfaceProxy::fSurfaceFlags

  The goal of this is to provide a location where GrTexture/GrTextureProxy-specific flags
(i.e., isExternal & isRectangle) can be stored.

Change-Id: I8df7b79036a6853dd378ff6cf10d4b37c60dd511
Reviewed-on: https://skia-review.googlesource.com/114796
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrClipStackClip.cpp b/src/gpu/GrClipStackClip.cpp
index 28bf34b..fe8d100 100644
--- a/src/gpu/GrClipStackClip.cpp
+++ b/src/gpu/GrClipStackClip.cpp
@@ -466,7 +466,7 @@
         // MDB TODO: We're going to fill this proxy with an ASAP upload (which is out of order wrt
         // to ops), so it can't have any pending IO.
         proxy = proxyProvider->createProxy(desc, kTopLeft_GrSurfaceOrigin, SkBackingFit::kApprox,
-                                           SkBudgeted::kYes, GrResourceProvider::kNoPendingIO_Flag);
+                                           SkBudgeted::kYes, GrInternalSurfaceFlags::kNoPendingIO);
 
         auto uploader = skstd::make_unique<GrTDeferredProxyUploader<ClipMaskData>>(reducedClip);
         GrTDeferredProxyUploader<ClipMaskData>* uploaderRaw = uploader.get();