Make GrDrawContext be GrRenderTargetProxy-backed

This is split out of https://codereview.chromium.org/2215323003/ (Start using RenderTargetProxy (omnibus))

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3841

CQ_INCLUDE_TRYBOTS=master.client.skia.android:Test-Android-Clang-Nexus5-GPU-Adreno330-arm-Debug-GN_Android-Trybot

Change-Id: I1a47f19ed1ac0c249e6ccac8db74095d7f456db4
Reviewed-on: https://skia-review.googlesource.com/3841
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrRenderTargetOpList.cpp b/src/gpu/GrRenderTargetOpList.cpp
index 9f50d5d..33a8608 100644
--- a/src/gpu/GrRenderTargetOpList.cpp
+++ b/src/gpu/GrRenderTargetOpList.cpp
@@ -46,10 +46,10 @@
 static const int kDefaultMaxBatchLookback  = 10;
 static const int kDefaultMaxBatchLookahead = 10;
 
-GrRenderTargetOpList::GrRenderTargetOpList(GrRenderTarget* rt, GrGpu* gpu,
+GrRenderTargetOpList::GrRenderTargetOpList(GrRenderTargetProxy* rtp, GrGpu* gpu,
                                            GrResourceProvider* resourceProvider,
                                            GrAuditTrail* auditTrail, const Options& options)
-    : INHERITED(rt, auditTrail)
+    : INHERITED(rtp, auditTrail)
     , fLastFullClearBatch(nullptr)
     , fGpu(SkRef(gpu))
     , fResourceProvider(resourceProvider) {