Implement instanced rendering for simple shapes

src/gpu/batches/GrBatch.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 GrBatch_DEFINED
 #define GrBatch_DEFINED
 
@@ skipping 123 matching lines @@
     static uint32_t GenBatchClassID() { return GenID(&gCurrBatchClassID); }
 
     SkRect                              fBounds;
 
 private:
     virtual bool onCombineIfPossible(GrBatch*, const GrCaps& caps) = 0;
 
     virtual void onPrepare(GrBatchFlushState*) = 0;
     virtual void onDraw(GrBatchFlushState*) = 0;
 
+    // Override this method if the batch subclass gets allocated in a nonstandard way.
+    virtual void onDelete() const { delete this; }
+
     static uint32_t GenID(int32_t* idCounter) {
         // The atomic inc returns the old value not the incremented value. So we add
         // 1 to the returned value.
         uint32_t id = static_cast<uint32_t>(sk_atomic_inc(idCounter)) + 1;
         if (!id) {
             SkFAIL("This should never wrap as it should only be called once for each GrBatch "
                    "subclass.");
         }
         return id;
     }
 
     enum {
         kIllegalBatchID = 0,
     };
 
     SkDEBUGCODE(bool                    fUsed;)
     const uint32_t                      fClassID;
     static uint32_t GenBatchID() { return GenID(&gCurrBatchUniqueID); }
     mutable uint32_t                    fUniqueID;
     static int32_t                      gCurrBatchUniqueID;
     static int32_t                      gCurrBatchClassID;
+
+    friend void GrTDeleteNonAtomicRef(const GrBatch*); // For onDelete.
 };
 
+inline void GrTDeleteNonAtomicRef(const GrBatch* batch) {
+    batch->onDelete();
+}
+
 #endif