First pass at VulkanViewer

src/gpu/vk/GrVkBackendContext.cpp

Index: src/gpu/vk/GrVkBackendContext.cpp
diff --git a/src/gpu/vk/GrVkBackendContext.cpp b/src/gpu/vk/GrVkBackendContext.cpp
index 1ca56e86474861ced58aa2d71a2f1e0a4a72c4de..8102d4689229e369363087276bfcde5467e95259 100644
--- a/src/gpu/vk/GrVkBackendContext.cpp
+++ b/src/gpu/vk/GrVkBackendContext.cpp
@@ -24,7 +24,7 @@ const char* kDebugLayerNames[] = {
     "VK_LAYER_LUNARG_mem_tracker",
     "VK_LAYER_LUNARG_draw_state",
     "VK_LAYER_LUNARG_swapchain",
-    "VK_LAYER_GOOGLE_unique_objects",
+    //"VK_LAYER_GOOGLE_unique_objects",
     // not included in standard_validation
     //"VK_LAYER_LUNARG_api_dump",
     //"VK_LAYER_LUNARG_vktrace",
@@ -159,6 +159,10 @@ const GrVkBackendContext* GrVkBackendContext::Create() {
         }
     }
 #endif
+    if (extensions.hasDeviceExtension(VK_KHR_SWAPCHAIN_EXTENSION_NAME)) {
+        deviceExtensionNames.push_back(VK_KHR_SWAPCHAIN_EXTENSION_NAME);
+        extensionFlags |= kKHR_swapchain_GrVkExtensionFlag;
+    }
     if (extensions.hasDeviceExtension("VK_NV_glsl_shader")) {
         deviceExtensionNames.push_back("VK_NV_glsl_shader");
         extensionFlags |= kNV_glsl_shader_GrVkExtensionFlag;