Move internal calls from GrContext to GrContextPriv

A mechanical bulk move just to get these out of the public API.

TBR=bsalomon@google.com
Change-Id: I813efbd54a09dd448275697c0e50947753a5cfd3
Reviewed-on: https://skia-review.googlesource.com/112262
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index ce7fe34..bb51b88 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -306,7 +306,7 @@
         matrix.setTranslate(-SkIntToScalar(colorBounds.x()), -SkIntToScalar(colorBounds.y()));
 
         sk_sp<GrRenderTargetContext> renderTargetContext(
-            context->makeDeferredRenderTargetContext(SkBackingFit::kApprox,
+            context->contextPriv().makeDeferredRenderTargetContext(SkBackingFit::kApprox,
                                                      bounds.width(), bounds.height(),
                                                      GrRenderableConfigForColorSpace(colorSpace),
                                                      sk_ref_sp(colorSpace)));