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/PathOpsOpLoopThreadedTest.cpp b/tests/PathOpsOpLoopThreadedTest.cpp
index 3854f90..04caac9 100644
--- a/tests/PathOpsOpLoopThreadedTest.cpp
+++ b/tests/PathOpsOpLoopThreadedTest.cpp
@@ -76,7 +76,7 @@
             pathStr.appendf("    testPathOp(reporter, path, pathB, kIntersect_SkPathOp,"
                     " filename);\n");
             pathStr.appendf("}\n");
-            outputProgress(state.fPathStr, pathStr.c_str(), kIntersect_SkPathOp);
+            state.outputProgress(pathStr.c_str(), kIntersect_SkPathOp);
         }
         testPathOp(state.fReporter, pathA, pathB, kIntersect_SkPathOp, "loops");
                 }