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/tests/ResourceCacheTest.cpp b/tests/ResourceCacheTest.cpp
index 55f4f85..2ceb567 100644
--- a/tests/ResourceCacheTest.cpp
+++ b/tests/ResourceCacheTest.cpp
@@ -1465,7 +1465,7 @@
         };
 
         // ensure all are purged before the next
-        context->purgeAllUnlockedResources();
+        context->contextPriv().purgeAllUnlockedResources_ForTesting();
         REPORTER_ASSERT(reporter, 0 == cache->getBudgetedResourceCount());
         REPORTER_ASSERT(reporter, 0 == cache->getPurgeableBytes());