Modify GrClipMaskManager to reflect logical constness

include/gpu/GrProcessorDataManager.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 GrProcessorDataManager_DEFINED
 #define GrProcessorDataManager_DEFINED
 
@@ skipping 12 matching lines @@
     void operator delete(void* target);
 
     void* operator new(size_t size, void* placement) {
         return ::operator new(size, placement);
     }
     void operator delete(void* target, void* placement) {
         ::operator delete(target, placement);
     }
 
 private:
+    uint32_t currentSaveMarker() const { return 0; }
+    void restoreToSaveMarker(/*uint32_t marker*/) {}
+
+    // For GrPipelineBuilder::AutoRestoreProcessorDataManager
+    friend class GrPipelineBuilder;
     static const uint32_t kNumProcessor = 1;
     static const uint32_t kDataIndicesPerProcessor = 1;
     static const uint32_t kPreAllocDataPerProcessor = 1;
 
     /*static const size_t kPreAllocStorage = kNumProcessor * kPreAllocDataPerProcessor;
     static const uint32_t kNumProcessor = 8;
     static const uint32_t kDataIndicesPerProcessor = 4;
     static const uint32_t kPreAllocDataPerProcessor = kDataIndicesPerProcessor *
                                                       sizeof(GrCoordTransform);*/
     static const size_t kPreAllocIndices = kNumProcessor * kDataIndicesPerProcessor;
     static const size_t kPreAllocStorage = kNumProcessor * kPreAllocDataPerProcessor;
     SkSTArray<kPreAllocIndices, uint32_t, true> fIndices;
     SkSTArray<kPreAllocStorage, unsigned char, true> fStorage;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif