Make some GrSurfaceProxy and GrTextureProxy methods easier to access

Move peek[Surface|Texture|RenderTarget]() from GrSurfaceProxyPriv to
to GrSurfaceProxy.

Move proxyMipMapped(), textureType(), and hasRestrictedSampling()
from GrTextureProxyPriv to GrTextureProxy.

Change-Id: I259114d0508c4613d55f7f1faccac362fa6fb281
Reviewed-on: https://skia-review.googlesource.com/144641
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/tests/ClipStackTest.cpp b/tests/ClipStackTest.cpp
index 498e60d..2cfeaae 100644
--- a/tests/ClipStackTest.cpp
+++ b/tests/ClipStackTest.cpp
@@ -1511,7 +1511,7 @@
         stack.clipPath(path, m, SkClipOp::kIntersect, true);
         sk_sp<GrTextureProxy> mask = GrClipStackClip(&stack).testingOnly_createClipMask(context);
         mask->instantiate(context->contextPriv().resourceProvider());
-        GrTexture* tex = mask->priv().peekTexture();
+        GrTexture* tex = mask->peekTexture();
         REPORTER_ASSERT(reporter, 0 == strcmp(tex->getUniqueKey().tag(), kTag));
         // Make sure mask isn't pinned in cache.
         mask.reset(nullptr);