Enable extension support and debug layer.

src/gpu/vk/GrVkGpu.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 GrVkGpu_DEFINED
 #define GrVkGpu_DEFINED
 
@@ skipping 12 matching lines @@
 class GrPipeline;
 class GrNonInstancedMesh;
 
 class GrVkBufferImpl;
 class GrVkCommandBuffer;
 class GrVkPipeline;
 class GrVkRenderPass;
 class GrVkTexture;
 struct GrVkInterface;
 
+#ifdef SK_DEBUG
+#define ENABLE_VK_LAYERS
+#endif
+
 class GrVkGpu : public GrGpu {
 public:
     // Currently passing in the inst so that we can properly delete it when we are done.
     // Normally this would be done by the client.
     GrVkGpu(GrContext* context, const GrContextOptions& options,
             VkPhysicalDevice physDev, VkDevice device, VkQueue queue, VkCommandPool cmdPool,
             VkInstance inst);
     ~GrVkGpu() override;
 
     const GrVkInterface* vkInterface() const { return fInterface.get(); }
@@ skipping 168 matching lines @@
 
     SkAutoTUnref<const GrVkInterface> fInterface;
     SkAutoTUnref<GrVkCaps>            fVkCaps;
     VkPhysicalDeviceMemoryProperties  fPhysDevMemProps;
     VkDevice                          fDevice;
     VkQueue                           fQueue;   // for now, one queue
     VkCommandPool                     fCmdPool;
     GrVkCommandBuffer*                fCurrentCmdBuffer;
     GrVkResourceProvider              fResourceProvider;
 
+#ifdef ENABLE_VK_LAYERS
+    // For reporting validation layer errors
+    VkDebugReportCallbackEXT          fCallback;
+#endif
+
     // Shaderc compiler used for compiling glsl in spirv. We only want to create the compiler once
     // since there is significant overhead to the first compile of any compiler.
     shaderc_compiler_t fCompiler;
 
     // This is only for our current testing and building. The client should be holding on to the
     // VkInstance.
     VkInstance                        fVkInstance;
 
     typedef GrGpu INHERITED;
 };
 
 #endif