[vulkan] Fix Fuchsia build

Stub out VulkanSwapchain.

Test:Fuchsia release *and* debug builds

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -603,6 +603,7 @@ FILE: ../../../flutter/vulkan/vulkan_surface.cc
 FILE: ../../../flutter/vulkan/vulkan_surface.h
 FILE: ../../../flutter/vulkan/vulkan_swapchain.cc
 FILE: ../../../flutter/vulkan/vulkan_swapchain.h
+FILE: ../../../flutter/vulkan/vulkan_swapchain_stub.cc
 FILE: ../../../flutter/vulkan/vulkan_utilities.cc
 FILE: ../../../flutter/vulkan/vulkan_utilities.h
 FILE: ../../../flutter/vulkan/vulkan_window.cc

engine/src/flutter/vulkan/BUILD.gn

@@ -35,6 +35,7 @@ source_set("vulkan") {
     "vulkan_proc_table.h",
     "vulkan_surface.cc",
     "vulkan_surface.h",
+    "vulkan_swapchain.h",
     "vulkan_utilities.cc",
     "vulkan_utilities.h",
     "vulkan_window.cc",
@@ -46,9 +47,11 @@ source_set("vulkan") {
       "vulkan_native_surface_android.cc",
       "vulkan_native_surface_android.h",
       "vulkan_swapchain.cc",
-      "vulkan_swapchain.h",
     ]
   }
+  if (is_fuchsia) {
+    sources += [ "vulkan_swapchain_stub.cc" ]
+  }
 
   deps = [
     "$flutter_root/fml",

engine/src/flutter/vulkan/vulkan_swapchain.h

@@ -61,6 +61,7 @@ class VulkanSwapchain {
 
   SkISize GetSize() const;
 
+#if OS_ANDROID
  private:
   const VulkanProcTable& vk;
   const VulkanDevice& device_;
@@ -88,6 +89,7 @@ class VulkanSwapchain {
                                      sk_sp<SkColorSpace> color_space) const;
 
   VulkanBackbuffer* GetNextBackbuffer();
+#endif  // OS_ANDROID
 
   FML_DISALLOW_COPY_AND_ASSIGN(VulkanSwapchain);
 };

engine/src/flutter/vulkan/vulkan_swapchain_stub.cc

@@ -0,0 +1,34 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/vulkan/vulkan_swapchain.h"
+
+namespace vulkan {
+
+VulkanSwapchain::VulkanSwapchain(const VulkanProcTable& p_vk,
+                                 const VulkanDevice& device,
+                                 const VulkanSurface& surface,
+                                 GrContext* skia_context,
+                                 std::unique_ptr<VulkanSwapchain> old_swapchain,
+                                 uint32_t queue_family_index) {}
+
+VulkanSwapchain::~VulkanSwapchain() = default;
+
+bool VulkanSwapchain::IsValid() const {
+  return false;
+}
+
+VulkanSwapchain::AcquireResult VulkanSwapchain::AcquireSurface() {
+  return {AcquireStatus::ErrorSurfaceLost, nullptr};
+}
+
+bool VulkanSwapchain::Submit() {
+  return false;
+}
+
+SkISize VulkanSwapchain::GetSize() const {
+  return SkISize::Make(0, 0);
+}
+
+}  // namespace vulkan