Fix DrawFilter's usage in HWUI.

Also add additional compile time checks to ensure that the Java
and Skia APIs remain in sync.

bug:19890753
Change-Id: I8503cacf2859307e3f480a78603f9f05901b58cc
diff --git a/libs/hwui/DisplayListRenderer.cpp b/libs/hwui/DisplayListRenderer.cpp
index 2a673f4..8757e15 100644
--- a/libs/hwui/DisplayListRenderer.cpp
+++ b/libs/hwui/DisplayListRenderer.cpp
@@ -484,7 +484,7 @@
 }
 
 void DisplayListRenderer::setDrawFilter(SkDrawFilter* filter) {
-    mDrawFilter.reset(filter);
+    mDrawFilter.reset(SkSafeRef(filter));
 }
 
 void DisplayListRenderer::insertReorderBarrier(bool enableReorder) {