Add offset to memory allocations

include/gpu/vk/GrVkTypes.h

Index: include/gpu/vk/GrVkTypes.h
diff --git a/include/gpu/vk/GrVkTypes.h b/include/gpu/vk/GrVkTypes.h
index 94b765f668329c6f99922bb1c7c3de1c1674562b..f4577031151b17bd696082e1394c90fd3186de32 100644
--- a/include/gpu/vk/GrVkTypes.h
+++ b/include/gpu/vk/GrVkTypes.h
@@ -9,6 +9,7 @@
 #ifndef GrVkTypes_DEFINED
 #define GrVkTypes_DEFINED
 
+#include "GrTypes.h"
 #include "vk/GrVkDefines.h"
 
 /**
@@ -29,13 +30,18 @@
  * Types for interacting with Vulkan resources created externally to Skia. GrBackendObjects for 
  * Vulkan textures are really const GrVkImageInfo*
  */
+struct GrVkAlloc {
+    VkDeviceMemory fMemory;  // can be VK_NULL_HANDLE iff Tex is an RT and uses borrow semantics
+    VkDeviceSize   fOffset;
+};
+
 struct GrVkImageInfo {
     /**
      * If the image's format is sRGB (GrVkFormatIsSRGB returns true), then the image must have
      * been created with VkImageCreateFlags containing VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT.
      */
     VkImage        fImage;
-    VkDeviceMemory fAlloc;    // can be VK_NULL_HANDLE iff Tex is an RT and uses borrow semantics
+    GrVkAlloc      fAlloc;
     VkImageTiling  fImageTiling;
     VkImageLayout  fImageLayout;
     VkFormat       fFormat;