MultiThreaded rendering of different renderNodes

This is adding the renderer side infrastructure to allow
rendering multiple render nodes with different threads.
This is a pre-step for decoupling a non client decor
resize reder from a content resize render.

Multiple render nodes can be added to be drawn, and to
prevent overdrawing, a content bounds area can be set

Bug: 22527834

Change-Id: Ie7271e20895bf38957e5a84aeefc883e282039ad
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index e7356db..046f24a 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -106,6 +106,11 @@
 
     ANDROID_API void serializeDisplayListTree();
 
+    ANDROID_API void addRenderNode(RenderNode* node, bool placeFront);
+    ANDROID_API void removeRenderNode(RenderNode* node);
+    ANDROID_API void drawRenderNode(RenderNode* node);
+    ANDROID_API void setContentOverdrawProtectionBounds(int left, int top, int right, int bottom);
+
 private:
     RenderThread& mRenderThread;
     CanvasContext* mContext;