Move Layer creation/deletion into the RenderPipeline.

Test: refactoring. existing tests still pass.
Change-Id: I032c33896a0cb74c91e2a913a584373518466b88
diff --git a/libs/hwui/renderthread/IRenderPipeline.h b/libs/hwui/renderthread/IRenderPipeline.h
index 3250fed..97cdf7f 100644
--- a/libs/hwui/renderthread/IRenderPipeline.h
+++ b/libs/hwui/renderthread/IRenderPipeline.h
@@ -67,6 +67,8 @@
             LayerUpdateQueue* layerUpdateQueue, bool opaque,
             const BakedOpRenderer::LightInfo& lightInfo) = 0;
     virtual TaskManager* getTaskManager() = 0;
+    virtual bool createOrUpdateLayer(RenderNode* node,
+            const DamageAccumulator& damageAccumulator) = 0;
 
     virtual ~IRenderPipeline() {}
 };