Don't track TextureLayer lifecycles in RenderState

bug:17208461

They are destroyed via finalizer-enqueued destroy method, so it's not
valid to check that they've been destroyed at gl context destruction
time.

Change-Id: I670f69825547facd5f31d44acb406418881fee00
diff --git a/libs/hwui/Layer.cpp b/libs/hwui/Layer.cpp
index 25caae3..91c4aee 100644
--- a/libs/hwui/Layer.cpp
+++ b/libs/hwui/Layer.cpp
@@ -29,15 +29,15 @@
 namespace android {
 namespace uirenderer {
 
-Layer::Layer(RenderState& renderState, const uint32_t layerWidth, const uint32_t layerHeight)
+Layer::Layer(Type layerType, RenderState& renderState, const uint32_t layerWidth, const uint32_t layerHeight)
         : caches(Caches::getInstance())
         , renderState(renderState)
-        , texture(caches) {
+        , texture(caches)
+        , type(layerType) {
     mesh = NULL;
     meshElementCount = 0;
     cacheable = true;
     dirty = false;
-    textureLayer = false;
     renderTarget = GL_TEXTURE_2D;
     texture.width = layerWidth;
     texture.height = layerHeight;
@@ -55,11 +55,17 @@
     caches.resourceCache.incrementRefcount(this);
     rendererLightPosDirty = true;
     wasBuildLayered = false;
-    renderState.registerLayer(this);
+    if (!isTextureLayer()) {
+        // track only non-texture layer lifecycles in renderstate,
+        // because texture layers are destroyed via finalizer
+        renderState.registerLayer(this);
+    }
 }
 
 Layer::~Layer() {
-    renderState.unregisterLayer(this);
+    if (!isTextureLayer()) {
+        renderState.unregisterLayer(this);
+    }
     SkSafeUnref(colorFilter);
     removeFbo();
     deleteTexture();
diff --git a/libs/hwui/Layer.h b/libs/hwui/Layer.h
index 911b99880..36a4ed1 100644
--- a/libs/hwui/Layer.h
+++ b/libs/hwui/Layer.h
@@ -54,7 +54,12 @@
  */
 class Layer {
 public:
-    Layer(RenderState& renderState, const uint32_t layerWidth, const uint32_t layerHeight);
+    enum Type {
+        kType_Texture,
+        kType_DisplayList,
+    };
+
+    Layer(Type type, RenderState& renderState, const uint32_t layerWidth, const uint32_t layerHeight);
     ~Layer();
 
     static uint32_t computeIdealWidth(uint32_t layerWidth);
@@ -219,11 +224,7 @@
     }
 
     inline bool isTextureLayer() const {
-        return textureLayer;
-    }
-
-    inline void setTextureLayer(bool textureLayer) {
-        this->textureLayer = textureLayer;
+        return type == kType_Texture;
     }
 
     inline SkColorFilter* getColorFilter() const {
@@ -343,10 +344,9 @@
     bool cacheable;
 
     /**
-     * When set to true, this layer must be treated as a texture
-     * layer.
+     * Denotes whether the layer is a DisplayList, or Texture layer.
      */
-    bool textureLayer;
+    const Type type;
 
     /**
      * When set to true, this layer is dirty and should be cleared
diff --git a/libs/hwui/LayerCache.cpp b/libs/hwui/LayerCache.cpp
index efa30ac..d49daf6 100644
--- a/libs/hwui/LayerCache.cpp
+++ b/libs/hwui/LayerCache.cpp
@@ -112,7 +112,7 @@
     } else {
         LAYER_LOGD("Creating new layer %dx%d", entry.mWidth, entry.mHeight);
 
-        layer = new Layer(renderState, entry.mWidth, entry.mHeight);
+        layer = new Layer(Layer::kType_DisplayList, renderState, entry.mWidth, entry.mHeight);
         layer->setBlend(true);
         layer->setEmpty(true);
         layer->setFbo(0);
diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index e3b0daf..103c843 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -272,9 +272,8 @@
 Layer* LayerRenderer::createTextureLayer(RenderState& renderState) {
     LAYER_RENDERER_LOGD("Creating new texture layer");
 
-    Layer* layer = new Layer(renderState, 0, 0);
+    Layer* layer = new Layer(Layer::kType_Texture, renderState, 0, 0);
     layer->setCacheable(false);
-    layer->setTextureLayer(true);
     layer->setEmpty(true);
     layer->setFbo(0);
     layer->setAlpha(255, SkXfermode::kSrcOver_Mode);