Refactor vulkan buffer mapping and unmapping

src/gpu/vk/GrVkUniformBuffer.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 GrVkUniformBuffer_DEFINED
 #define GrVkUniformBuffer_DEFINED
 
 #include "GrVkBuffer.h"
 
 class GrVkGpu;
 
 class GrVkUniformBuffer : public GrVkBuffer {
 
 public:
     static GrVkUniformBuffer* Create(GrVkGpu* gpu, size_t size);
     static const GrVkResource* CreateResource(GrVkGpu* gpu, size_t size);
     static const size_t kStandardSize = 256;
 
-    void* map(const GrVkGpu* gpu) {
+    void* map(GrVkGpu* gpu) {
         return this->vkMap(gpu);
     }
     void unmap(GrVkGpu* gpu) {
         this->vkUnmap(gpu);
     }
     // The output variable createdNewBuffer must be set to true if a new VkBuffer is created in
     // order to upload the data
     bool updateData(GrVkGpu* gpu, const void* src, size_t srcSizeInBytes,
                     bool* createdNewBuffer) {
         return this->vkUpdateData(gpu, src, srcSizeInBytes, createdNewBuffer);
@@ skipping 16 matching lines @@
                                                const GrVkBuffer::Desc& descriptor) override;
 
     GrVkUniformBuffer(GrVkGpu* gpu, const GrVkBuffer::Desc& desc,
                       const GrVkUniformBuffer::Resource* resource)
         : INHERITED(desc, resource) {}
 
     typedef GrVkBuffer INHERITED;
 };
 
 #endif