Allow setting of GrBatchFontCache atlas sizes

src/gpu/GrBatchAtlas.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrBatchAtlas_DEFINED
 #define GrBatchAtlas_DEFINED
 
 #include "GrTexture.h"
 #include "batches/GrDrawBatch.h"
 #include "SkPoint.h"
 #include "SkTDArray.h"
 #include "SkTInternalLList.h"
 
 class BatchPlot;
 class GrRectanizer;
 
 typedef SkTInternalLList<BatchPlot> GrBatchPlotList;
 
+struct GrBatchAtlasConfig {
+    int numPlotsX() const { return fWidth / fPlotWidth; }
+    int numPlotsY() const { return fHeight / fPlotWidth; }
+    int fWidth;
+    int fHeight;
+    int fPlotWidth;
+    int fPlotHeight;
+};
+
 class GrBatchAtlas {
 public:
     // An AtlasID is an opaque handle which callers can use to determine if the atlas contains
     // a specific piece of data
     typedef uint64_t AtlasID;
     static const uint32_t kInvalidAtlasID = 0;
     static const uint64_t kInvalidAtlasGeneration = 0;
 
     // A function pointer for use as a callback during eviction.  Whenever GrBatchAtlas evicts a
     // specific AtlasID, it will call all of the registered listeners so they can optionally process
@@ skipping 108 matching lines @@
     };
 
     SkTDArray<EvictionData> fEvictionCallbacks;
     // allocated array of GrBatchPlots
     SkAutoTUnref<BatchPlot>* fPlotArray;
     // LRU list of GrPlots (MRU at head - LRU at tail)
     GrBatchPlotList fPlotList;
 };
 
 #endif