SkNonCopyable should be used with private inheritance.

This is mostly s/public SkNoncopyable/SkNoncopyable/g.

Two classes (SkDrawLooper::Context and SkPicture::OperationList) don't actually work with SkNoncopyable because they introduce a virtual destructor.  I added SkNoncopyableVirtual to make them work as intended.  Sort of questionable whether they really need to be noncopyable in the first place, but I guess it doesn't hurt to keep the behavior the same.

BUG=skia:
R=reed@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/226183018

git-svn-id: http://skia.googlecode.com/svn/trunk@14081 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrSWMaskHelper.h b/src/gpu/GrSWMaskHelper.h
index b274e84..697d6f3 100644
--- a/src/gpu/GrSWMaskHelper.h
+++ b/src/gpu/GrSWMaskHelper.h
@@ -38,7 +38,7 @@
  * The result of this process will be the final mask (on the GPU) in the
  * upper left hand corner of the texture.
  */
-class GrSWMaskHelper : public SkNoncopyable {
+class GrSWMaskHelper : SkNoncopyable {
 public:
     GrSWMaskHelper(GrContext* context)
     : fContext(context) {