Revise system for checking for uninstantiated proxies

The new pattern is:
  we will "instantiate" pipelines at flush time
  at flush time we will only access the backing GrSurface by peeking

  If instantiation fails we should never try to access the GrSurfaces


Change-Id: I87f7ff41bd0e84d9ca3dbdd61d3361d3d4ceefd6
Reviewed-on: https://skia-review.googlesource.com/17932
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 5169615..399a307 100644
--- a/tests/ProcessorTest.cpp
+++ b/tests/ProcessorTest.cpp
@@ -353,7 +353,7 @@
         }
         for (int j = 0; j < timesToInvokeFactory; ++j) {
             fp = FPFactory::MakeIdx(i, &testData);
-            if (fp->isBad()) {
+            if (!fp->instantiate(context->resourceProvider())) {
                 continue;
             }