Fix type conversion compile errors

tools/vulkan/VulkanTestContext.cpp

 
 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrContext.h"
 #include "SkSurface.h"
@@ skipping 222 matching lines @@
 
     // set up initial image layouts and create surfaces
     fImageLayouts = new VkImageLayout[fImageCount];
     fSurfaces = new sk_sp<SkSurface>[fImageCount];
     for (uint32_t i = 0; i < fImageCount; ++i) {
         fImageLayouts[i] = VK_IMAGE_LAYOUT_UNDEFINED;
 
         GrBackendRenderTargetDesc desc;
         GrVkTextureInfo info;
         info.fImage = fImages[i];
-        info.fAlloc = nullptr;
+        info.fAlloc = VK_NULL_HANDLE;
         info.fImageLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
         info.fImageTiling = VK_IMAGE_TILING_OPTIMAL;
         info.fFormat = format;
         desc.fWidth = fWidth;
         desc.fHeight = fHeight;
         desc.fConfig = fPixelConfig;
         desc.fOrigin = kTopLeft_GrSurfaceOrigin;
         desc.fSampleCnt = 0;
         desc.fStencilBits = 0;
         desc.fRenderTargetHandle = (GrBackendObject) &info;
@@ skipping 305 matching lines @@
         &backbuffer->fRenderSemaphore, // pWaitSemaphores
         1, // swapchainCount
         &fSwapchain, // pSwapchains
         &backbuffer->fImageIndex, // pImageIndices
         NULL // pResults
     };
 
     fQueuePresentKHR(fPresentQueue, &presentInfo);
 
 }