SW backend for viewer on Windows
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2182273002

Review-Url: https://codereview.chromium.org/2182273002
diff --git a/tools/viewer/sk_app/VulkanWindowContext.cpp b/tools/viewer/sk_app/VulkanWindowContext.cpp
index 74c0674..f2fc1e5 100644
--- a/tools/viewer/sk_app/VulkanWindowContext.cpp
+++ b/tools/viewer/sk_app/VulkanWindowContext.cpp
@@ -85,7 +85,7 @@
     vkGetDeviceQueue(fBackendContext->fDevice, fPresentQueueIndex, 0, &fPresentQueue);
 }
 
-bool VulkanWindowContext::createSwapchain(uint32_t width, uint32_t height,
+bool VulkanWindowContext::createSwapchain(int width, int height,
                                           const DisplayParams& params) {
     // check for capabilities
     VkSurfaceCapabilitiesKHR caps;