Convert DstTexture to DstProxy (take 2)

The last GrTexture-based TextureSampler::reset call must be removed before the TextureSamplers can become purely GrTextureProxy-backed

Reland of: https://skia-review.googlesource.com/c/16908/ (Convert DstTexture to DstProxy)

Split out of: https://skia-review.googlesource.com/c/10484/ (Omnibus: Push instantiation of GrTextures later (post TextureSampler))

Change-Id: I3a497b6a950fad899f23882c0a9552894ef640f8
Reviewed-on: https://skia-review.googlesource.com/17205
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tests/ProcessorTest.cpp b/tests/ProcessorTest.cpp
index 399a307..41bb183 100644
--- a/tests/ProcessorTest.cpp
+++ b/tests/ProcessorTest.cpp
@@ -324,6 +324,11 @@
     }
     proxies[1] = GrSurfaceProxy::MakeDeferred(context->resourceProvider(), desc, SkBudgeted::kYes,
                                               alphaData.get(), 256);
+
+    if (!proxies[0] || !proxies[1]) {
+        return;
+    }
+
     GrProcessorTestData testData(&random, context, rtc.get(), proxies);
 
     // Use a different array of premul colors for the output of the fragment processor that preceeds