Add offset to memory allocations

src/gpu/vk/GrVkImage.h

Index: src/gpu/vk/GrVkImage.h
diff --git a/src/gpu/vk/GrVkImage.h b/src/gpu/vk/GrVkImage.h
index 30b6b89a13ac5aa540a89b7a40be8743a1cc93b0..7bc01b6d4e0983073f418a416f9556c2fdb02492 100644
--- a/src/gpu/vk/GrVkImage.h
+++ b/src/gpu/vk/GrVkImage.h
@@ -33,15 +33,16 @@ public:
         : fInfo(info)
         , fIsBorrowed(kBorrowed_Wrapped == wrapped) {
         if (kBorrowed_Wrapped == wrapped) {
-            fResource = new BorrowedResource(info.fImage, info.fAlloc);
+            fResource = new BorrowedResource(info.fImage, info.fAlloc, info.fOffset);
         } else {
-            fResource = new Resource(info.fImage, info.fAlloc);
+            fResource = new Resource(info.fImage, info.fAlloc, info.fOffset);
         }
     }
     virtual ~GrVkImage();
 
     VkImage image() const { return fInfo.fImage; }
     VkDeviceMemory memory() const { return fInfo.fAlloc; }
+    VkDeviceSize offset() const { return fInfo.fOffset; }
     VkFormat imageFormat() const { return fInfo.fFormat; }
     const Resource* resource() const { return fResource; }
     bool isLinearTiled() const {
@@ -87,7 +88,7 @@ protected:
     void releaseImage(const GrVkGpu* gpu);
     void abandonImage();
 
-    void setNewResource(VkImage image, VkDeviceMemory alloc);
+    void setNewResource(VkImage image, VkDeviceMemory alloc, VkDeviceSize offset);
 
     GrVkImageInfo   fInfo;
     bool            fIsBorrowed;
@@ -99,10 +100,12 @@ private:
         Resource()
             : INHERITED()
             , fImage(VK_NULL_HANDLE)
-            , fAlloc(VK_NULL_HANDLE) {
+            , fAlloc(VK_NULL_HANDLE)
+            , fOffset(0) {
         }
 
-        Resource(VkImage image, VkDeviceMemory alloc) : fImage(image), fAlloc(alloc) {}
+        Resource(VkImage image, VkDeviceMemory alloc, VkDeviceSize offset) 
+            : fImage(image), fAlloc(alloc), fOffset(offset) {}
 
         ~Resource() override {}
 
@@ -111,6 +114,7 @@ private:
 
         VkImage                  fImage;
         VkDeviceMemory           fAlloc;
+        VkDeviceSize             fOffset;
 
         typedef GrVkResource INHERITED;
     };
@@ -118,7 +122,8 @@ private:
     // for wrapped textures
     class BorrowedResource : public Resource {
     public:
-        BorrowedResource(VkImage image, VkDeviceMemory alloc) : Resource(image, alloc) {
+        BorrowedResource(VkImage image, VkDeviceMemory alloc, VkDeviceSize offset) 
+            : Resource(image, alloc, offset) {
         }
     private:
         void freeGPUData(const GrVkGpu* gpu) const override;