Reland "Make compiling the amd vulkan memory allocator optional."

This reverts commit 6a5a91e1643ae6f692feb8fc67d6b8319cbdb63f.

Reason for revert: chrome gn updated, so this should roll fine now

Original change's description:
> Revert "Make compiling the amd vulkan memory allocator optional."
> 
> This reverts commit 23da19863e321349393c61312293b090ec792287.
> 
> Reason for revert: break chrome roll, need to land chrome change first
> 
> Original change's description:
> > Make compiling the amd vulkan memory allocator optional.
> > 
> > Change-Id: I79b9f78b52f215076a371cbd0ff057d61dd855f0
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285380
> > Reviewed-by: Brian Osman <brianosman@google.com>
> > Commit-Queue: Greg Daniel <egdaniel@google.com>
> 
> TBR=egdaniel@google.com,brianosman@google.com,penghuang@chromium.org
> 
> Change-Id: Ifc17a07f5cdfcf7b38272e5c44e5b894019cf44a
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285538
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,brianosman@google.com,penghuang@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I4767039236137d3eaece2e16abef57278ce199ed
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285662
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 755200d..2b41c7d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -89,6 +89,9 @@
   if (skia_use_gl && skia_use_angle) {
     defines += [ "SK_ANGLE" ]
   }
+  if (skia_use_vma) {
+    defines += [ "SK_USE_VMA" ]
+  }
 }
 
 # Any code that's linked into Skia-the-library should use this config via += skia_library_configs.
@@ -562,7 +565,9 @@
 
   if (skia_use_vulkan) {
     public_defines += [ "SK_VULKAN" ]
-    deps += [ "third_party/vulkanmemoryallocator" ]
+    if (skia_use_vma) {
+      deps += [ "third_party/vulkanmemoryallocator" ]
+    }
     sources += skia_vk_sources
     if (skia_enable_vulkan_debug_layers) {
       public_defines += [ "SK_ENABLE_VK_LAYERS" ]