Rename GrContext::contextPriv to priv

Mechanical. This makes the priv() accessor the same for all the context types.

Change-Id: I40850eb05a33b8d7cc3eabdd42226d24b2ba58aa
Reviewed-on: https://skia-review.googlesource.com/c/189164
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tools/debugger/SkDebugCanvas.cpp b/tools/debugger/SkDebugCanvas.cpp
index b77c1f3..cbb420c 100644
--- a/tools/debugger/SkDebugCanvas.cpp
+++ b/tools/debugger/SkDebugCanvas.cpp
@@ -218,7 +218,7 @@
     GrAuditTrail* at = nullptr;
     GrContext* ctx = canvas->getGrContext();
     if (ctx) {
-        at = ctx->contextPriv().getAuditTrail();
+        at = ctx->priv().getAuditTrail();
     }
     return at;
 }