[graphite] Define freeGpuData() in VulkanTexture class

A prior CL (https://skia-review.googlesource.com/c/skia/+/634499) included the VulkanTexture class for the first time, exposing an error within some Debian bots where VulkanTexture failed to define an override to the purely virtual Resource::freeGpuData() method.

Change-Id: I2307afc80d0b8e0abd5a4ab4c61429e48e2cc902
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/638980
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Nicolette Prevost <nicolettep@google.com>
diff --git a/src/gpu/graphite/vk/VulkanTexture.cpp b/src/gpu/graphite/vk/VulkanTexture.cpp
index fcdc270..3ea94df 100644
--- a/src/gpu/graphite/vk/VulkanTexture.cpp
+++ b/src/gpu/graphite/vk/VulkanTexture.cpp
@@ -176,4 +176,9 @@
         , fImage(image)
         , fMemoryAlloc(alloc) {}
 
+void VulkanTexture::freeGpuData() {
+    auto sharedContext = static_cast<const VulkanSharedContext*>(this->sharedContext());
+    skgpu::VulkanMemory::FreeImageMemory(sharedContext->memoryAllocator(), fMemoryAlloc);
+}
+
 } // namespace skgpu::graphite