Re-jigger layers

 Bug: 15185239
 Bug: 15238382

 Make DeferredLayerUpdater ref counted so that
 HardwareLayer:finalizer() works non-crashily on
 leaked layers
 Give DeferredLayerUpdater the ability to have a layer destroyer
 set so that leaked layers can still be recycled on the
 RenderThread
 Order layer updates based off of pushLayerUpdate() calls to fix
 issue with nested layers

Change-Id: I4449cee607f7e5126e02fed7464cf48038e3dfdf
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index f91e90e..9ebee1d 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -427,27 +427,11 @@
     mHaveNewSurface |= mGlobalContext->makeCurrent(mEglSurface);
 }
 
-void CanvasContext::prepareDraw(const Vector<DeferredLayerUpdater*>* layerUpdaters,
-        TreeInfo& info) {
-    LOG_ALWAYS_FATAL_IF(!mCanvas, "Cannot prepareDraw without a canvas!");
-    makeCurrent();
-
-    processLayerUpdates(layerUpdaters, info);
-    if (info.out.hasAnimations) {
-        // TODO: Uh... crap?
-    }
-    prepareTree(info);
-}
-
-void CanvasContext::processLayerUpdates(const Vector<DeferredLayerUpdater*>* layerUpdaters,
-        TreeInfo& info) {
-    for (size_t i = 0; i < layerUpdaters->size(); i++) {
-        DeferredLayerUpdater* update = layerUpdaters->itemAt(i);
-        bool success = update->apply(info);
-        LOG_ALWAYS_FATAL_IF(!success, "Failed to update layer!");
-        if (update->backingLayer()->deferredUpdateScheduled) {
-            mCanvas->pushLayerUpdate(update->backingLayer());
-        }
+void CanvasContext::processLayerUpdate(DeferredLayerUpdater* layerUpdater, TreeInfo& info) {
+    bool success = layerUpdater->apply(info);
+    LOG_ALWAYS_FATAL_IF(!success, "Failed to update layer!");
+    if (layerUpdater->backingLayer()->deferredUpdateScheduled) {
+        mCanvas->pushLayerUpdate(layerUpdater->backingLayer());
     }
 }