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/GrSoftwarePathRenderer.cpp b/src/gpu/GrSoftwarePathRenderer.cpp
index 2ac4b5e..228625f 100644
--- a/src/gpu/GrSoftwarePathRenderer.cpp
+++ b/src/gpu/GrSoftwarePathRenderer.cpp
@@ -179,7 +179,7 @@
     // 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.
     return proxyProvider->createProxy(desc, kTopLeft_GrSurfaceOrigin, fit, SkBudgeted::kYes,
-                                      GrResourceProvider::kNoPendingIO_Flag);
+                                      GrInternalSurfaceFlags::kNoPendingIO);
 }
 
 namespace {