Create free list heap for suballocation

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2029763002

Review-Url: https://codereview.chromium.org/2029763002
diff --git a/src/gpu/vk/GrVkBuffer.h b/src/gpu/vk/GrVkBuffer.h
index f7d43c7..0bfbeca 100644
--- a/src/gpu/vk/GrVkBuffer.h
+++ b/src/gpu/vk/GrVkBuffer.h
@@ -54,11 +54,12 @@
 
     class Resource : public GrVkResource {
     public:
-        Resource(VkBuffer buf, const GrVkAlloc& alloc) 
-            : INHERITED(), fBuffer(buf), fAlloc(alloc) {}
+        Resource(VkBuffer buf, const GrVkAlloc& alloc, Type type)
+            : INHERITED(), fBuffer(buf), fAlloc(alloc), fType(type) {}
 
-        VkBuffer  fBuffer;
-        GrVkAlloc fAlloc;
+        VkBuffer           fBuffer;
+        GrVkAlloc          fAlloc;
+        Type               fType;
 
     private:
         void freeGPUData(const GrVkGpu* gpu) const;