Update Layer Hoisting to store its atlas texture in the resource cache

src/gpu/GrLayerAtlas.h

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrLayerAtlas_DEFINED
 #define GrLayerAtlas_DEFINED
 
-#include "GrTypes.h"
+#include "GrTexture.h"
 
 #include "SkPoint.h"
-#include "SkSize.h"
 #include "SkTDArray.h"
 #include "SkTInternalLList.h"
 
 class GrLayerAtlas;
-class GrTexture;
 class GrTextureProvider;
 class GrRectanizer;
 
 // The backing GrTexture for a GrLayerAtlas is broken into a spatial grid of Plots. When
 // the atlas needs space on the texture (i.e., in response to an addToAtlas call), it 
 // iterates through the plots in use by the requesting client looking for space and, 
 // if no space is found, opens up a new Plot for that client. The Plots keep track of 
 // subimage placement via their GrRectanizer. 
 //
 // If all Plots are full, the replacement strategy is up to the client. The Plot::reset
@@ skipping 71 matching lines @@
     GrLayerAtlas(GrTextureProvider*, GrPixelConfig, GrSurfaceFlags flags, 
                  const SkISize& backingTextureSize,
                  int numPlotsX, int numPlotsY);
     ~GrLayerAtlas();
 
     // Requests a width x height block in the atlas. Upon success it returns 
     // the containing Plot and absolute location in the backing texture. 
     // nullptr is returned if there is no more space in the atlas.
     Plot* addToAtlas(ClientPlotUsage*, int width, int height, SkIPoint16* loc);
 
-    GrTexture* getTexture() const {
+    GrTexture* getTextureOrNull() const {
         return fTexture;
     }
 
+    GrTexture* getTexture() const {
+        SkASSERT(fTexture);
+        return fTexture;
+    }
+
+    bool reattachBackingTexture();
+
+    void detachBackingTexture() {
+        fTexture.reset(nullptr);
+    }
+
+    void resetPlots();
+
     enum IterOrder {
         kLRUFirst_IterOrder,
         kMRUFirst_IterOrder
     };
 
     typedef SkTInternalLList<Plot> PlotList;
     typedef PlotList::Iter PlotIter;
     Plot* iterInit(PlotIter* iter, IterOrder order) {
         return iter->init(fPlotList, kLRUFirst_IterOrder == order
                                                        ? PlotList::Iter::kTail_IterStart
                                                        : PlotList::Iter::kHead_IterStart);
     }
 
 private:
+    void createBackingTexture();
+
     void makeMRU(Plot* plot);
 
     GrTextureProvider* fTexProvider;
     GrPixelConfig      fPixelConfig;
     GrSurfaceFlags     fFlags;
-    GrTexture*         fTexture;
+    SkAutoTUnref<GrTexture> fTexture;
 
     SkISize            fBackingTextureSize;
 
     // allocated array of Plots
     Plot*              fPlotArray;
     // LRU list of Plots (MRU at head - LRU at tail)
     PlotList           fPlotList;
 };
 
 #endif