Replace many skia::RefPtr with sk_sp<> in cc/

cc/trees/layer_tree_host_pixeltest_blending.cc

Index: cc/trees/layer_tree_host_pixeltest_blending.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_blending.cc b/cc/trees/layer_tree_host_pixeltest_blending.cc
index 9d356c48ea5e7fa3612733813aacbdc74ca1d4ee..a5d3f7c099f736a6e80da89d10375d7cae285fec 100644
--- a/cc/trees/layer_tree_host_pixeltest_blending.cc
+++ b/cc/trees/layer_tree_host_pixeltest_blending.cc
@@ -144,9 +144,7 @@ class LayerTreeHostBlendingPixelTest : public LayerTreeHostPixelResourceTest {
     scoped_refptr<PictureImageLayer> layer = PictureImageLayer::Create();
     layer->SetIsDrawable(true);
     layer->SetBounds(gfx::Size(width, height));
-    skia::RefPtr<const SkImage> image =
-        skia::AdoptRef(backing_store->newImageSnapshot());
-    layer->SetImage(std::move(image));
+    layer->SetImage(skia::SharePtr(backing_store->makeImageSnapshot()));

[f(malita), 2016/04/21 15:45:47]

nit: in this particular case I think they're functionally equivalent (both steal
the ref value), but skia::AdoptRef is easier to grok for me.

[tomhudson, 2016/04/25 20:20:51]

I don't understand - AdoptRef *does not* increment the reference count, but
SharePtr *does* increment the refcount, right?

[f(malita), 2016/04/27 14:00:41]

Yes (functionally), but the increment is front-loaded in the arg value
instantiation (refptr.h):

  RefPtr<T> AdoptRef(sk_sp<T>&& sp) { return RefPtr<T>(sp.release()); }
  RefPtr<T> SharePtr(sk_sp<T> sp) { return RefPtr<T>(sp.release()); }

When the argument is an rvalue (as it was the case here) they're equivalent.

All moot now, the new version is much nicer - thanks!

     return layer;
   }
 
@@ -168,9 +166,7 @@ class LayerTreeHostBlendingPixelTest : public LayerTreeHostPixelResourceTest {
                                       bounds.width() - kMaskOffset * 2,
                                       bounds.height() - kMaskOffset * 2),
                      paint);
-    skia::RefPtr<const SkImage> image =
-        skia::AdoptRef(surface->newImageSnapshot());
-    mask->SetImage(std::move(image));
+    mask->SetImage(skia::SharePtr(surface->makeImageSnapshot()));

[f(malita), 2016/04/21 15:45:47]

nit: ditto

     layer->SetMaskLayer(mask.get());
   }