remove SkMemoryWStream -- unused externally

BUG=skia:

Change-Id: Idbc9af4e703238871f56f623cd616fb7a5e686d3
Reviewed-on: https://skia-review.googlesource.com/6727
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/tests/PathOpsOpCubicThreadedTest.cpp b/tests/PathOpsOpCubicThreadedTest.cpp
index e76eb06..0bb8c19 100644
--- a/tests/PathOpsOpCubicThreadedTest.cpp
+++ b/tests/PathOpsOpCubicThreadedTest.cpp
@@ -56,7 +56,7 @@
                 pathStr.appendf("    testPathOp(reporter, path, pathB, %s, filename);\n",
                         SkPathOpsDebug::OpStr((SkPathOp) op));
                 pathStr.appendf("}\n");
-                outputProgress(state.fPathStr, pathStr.c_str(), (SkPathOp) op);
+                state.outputProgress(pathStr.c_str(), (SkPathOp) op);
             }
             if (!testPathOp(state.fReporter, pathA, pathB, (SkPathOp) op, "cubics")) {
                 if (state.fReporter->verbose()) {