Remove use of SkRefCnt_SafeAssign.

Update pointer to SkRefCnt fields which require it to sk_sp.

Test: refactoring CL. Existing unit tests still pass.
Change-Id: I4f3eb790ee67c09746708458c4492569b64cc58f
diff --git a/libs/hwui/RenderProperties.cpp b/libs/hwui/RenderProperties.cpp
index e495744..ff9cf45 100644
--- a/libs/hwui/RenderProperties.cpp
+++ b/libs/hwui/RenderProperties.cpp
@@ -44,8 +44,8 @@
 }
 
 bool LayerProperties::setColorFilter(SkColorFilter* filter) {
-    if (mColorFilter == filter) return false;
-    SkRefCnt_SafeAssign(mColorFilter, filter);
+    if (mColorFilter.get() == filter) return false;
+    mColorFilter = sk_ref_sp(filter);
     return true;
 }
 
@@ -62,7 +62,7 @@
     setOpaque(other.opaque());
     setAlpha(other.alpha());
     setXferMode(other.xferMode());
-    setColorFilter(other.colorFilter());
+    setColorFilter(other.getColorFilter());
     return *this;
 }