Refactor vulkan buffer mapping and unmapping

src/gpu/vk/GrVkBuffer.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 GrVkBuffer_DEFINED
 #define GrVkBuffer_DEFINED
 
 #include "GrVkResource.h"
 #include "vk/GrVkDefines.h"
 #include "vk/GrVkTypes.h"
 
 class GrVkGpu;
 
 /**
  * This class serves as the base of GrVk*Buffer classes. It was written to avoid code
  * duplication in those classes.
  */
 class GrVkBuffer : public SkNoncopyable {
 public:
     virtual ~GrVkBuffer() {
         // either release or abandon should have been called by the owner of this object.
         SkASSERT(!fResource);
+        delete [] (unsigned char*)fMapPtr;
     }
 
     VkBuffer                    buffer() const { return fResource->fBuffer; }
     const GrVkAlloc&            alloc() const { return fResource->fAlloc; }
     const GrVkRecycledResource* resource() const { return fResource; }
     size_t                      size() const { return fDesc.fSizeInBytes; }
     VkDeviceSize                offset() const { return fOffset;  }
 
     void addMemoryBarrier(const GrVkGpu* gpu,
                           VkAccessFlags srcAccessMask,
@@ skipping 40 matching lines @@
     };
 
     // convenience routine for raw buffer creation
     static const Resource* Create(const GrVkGpu* gpu,
                                   const Desc& descriptor);
 
     GrVkBuffer(const Desc& desc, const GrVkBuffer::Resource* resource)
         : fDesc(desc), fResource(resource), fOffset(0), fMapPtr(nullptr) {
     }
 
-    void* vkMap(const GrVkGpu* gpu);
+    void* vkMap(GrVkGpu* gpu);
     void vkUnmap(GrVkGpu* gpu);
     // If the caller passes in a non null createdNewBuffer, this function will set the bool to true
     // if it creates a new VkBuffer to upload the data to.
     bool vkUpdateData(GrVkGpu* gpu, const void* src, size_t srcSizeInBytes,
                       bool* createdNewBuffer = nullptr);
 
     void vkAbandon();
     void vkRelease(const GrVkGpu* gpu);
 
 private:
     virtual const Resource* createResource(GrVkGpu* gpu,
                                            const Desc& descriptor) {
         return Create(gpu, descriptor);
     }
 
+    void innerMap(GrVkGpu* gpu, size_t size, bool* createdNewBuffer = nullptr);
+    void innerUnmap(GrVkGpu* gpu, size_t size);
+
     void validate() const;
     bool vkIsMapped() const;
 
     Desc                    fDesc;
     const Resource*         fResource;
     VkDeviceSize            fOffset;
     void*                   fMapPtr;
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif