Let client pass in full extension to GrVkBackendContext.

Bug: skia:
Change-Id: I772ab4ccbca0f4f7e7d429d6c421b07d97f0606f
Reviewed-on: https://skia-review.googlesource.com/131880
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/tools/sk_app/VulkanWindowContext.cpp b/tools/sk_app/VulkanWindowContext.cpp
index 8e0749e..d038c97 100644
--- a/tools/sk_app/VulkanWindowContext.cpp
+++ b/tools/sk_app/VulkanWindowContext.cpp
@@ -12,6 +12,7 @@
 #include "SkSurface.h"
 #include "VulkanWindowContext.h"
 
+#include "vk/GrVkExtensions.h"
 #include "vk/GrVkImage.h"
 #include "vk/GrVkUtil.h"
 #include "vk/GrVkTypes.h"
@@ -56,8 +57,8 @@
         return;
     }
 
-    if (!(backendContext.fExtensions & kKHR_surface_GrVkExtensionFlag) ||
-        !(backendContext.fExtensions & kKHR_swapchain_GrVkExtensionFlag)) {
+    if (!backendContext.fInterface->fExtensions.hasExtension(VK_KHR_SURFACE_EXTENSION_NAME) ||
+        !backendContext.fInterface->fExtensions.hasExtension(VK_KHR_SWAPCHAIN_EXTENSION_NAME)) {
         return;
     }