Add a basic custom painting facility to Sky

sky/engine/platform/graphics/DisplayList.cpp

Index: sky/engine/platform/graphics/DisplayList.cpp
diff --git a/sky/engine/platform/graphics/DisplayList.cpp b/sky/engine/platform/graphics/DisplayList.cpp
index 36093966243c9071b516271250f2b46a77fe9d87..87f6b1dc3646ca9a0e9c74d7cd9233950dd81810 100644
--- a/sky/engine/platform/graphics/DisplayList.cpp
+++ b/sky/engine/platform/graphics/DisplayList.cpp
@@ -38,8 +38,7 @@
 
 namespace blink {
 
-DisplayList::DisplayList(const FloatRect& bounds)
-    : m_bounds(bounds)
+DisplayList::DisplayList()
 {
 }
 
@@ -47,11 +46,6 @@ DisplayList::~DisplayList()
 {
 }
 
-const FloatRect& DisplayList::bounds() const
-{
-    return m_bounds;
-}
-
 SkPicture* DisplayList::picture() const
 {
     return m_picture.get();