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/src/gpu/effects/GrMagnifierEffect.cpp b/src/gpu/effects/GrMagnifierEffect.cpp
index aadd541..ae53b33 100644
--- a/src/gpu/effects/GrMagnifierEffect.cpp
+++ b/src/gpu/effects/GrMagnifierEffect.cpp
@@ -83,7 +83,7 @@
             pdman.set1f(fYInvInsetVar, _outer.yInvInset());
         }
         GrSurfaceProxy& srcProxy = *_outer.textureSampler(0).proxy();
-        GrTexture& src = *srcProxy.priv().peekTexture();
+        GrTexture& src = *srcProxy.peekTexture();
         (void)src;
         auto bounds = _outer.bounds();
         (void)bounds;