[fuchsia] Use memory_requirements_2 extension.

This is required by some Vulkan 1.0 drivers. For example,
MoltenVK through goldfish ICD when running in the emulator.

shell/platform/fuchsia/flutter/vulkan_surface_producer.cc

@@ -16,6 +16,7 @@
 #include "third_party/skia/include/gpu/GrBackendSurface.h"
 #include "third_party/skia/include/gpu/GrContext.h"
 #include "third_party/skia/include/gpu/vk/GrVkBackendContext.h"
+#include "third_party/skia/include/gpu/vk/GrVkExtensions.h"
 #include "third_party/skia/include/gpu/vk/GrVkTypes.h"
 
 namespace flutter_runner {
@@ -126,6 +127,16 @@ bool VulkanSurfaceProducer::Initialize(scenic::Session* scenic_session) {
   backend_context.fFeatures = skia_features;
   backend_context.fGetProc = std::move(getProc);
   backend_context.fOwnsInstanceAndDevice = false;
+  // The memory_requirements_2 extension is required on Fuchsia as the AMD
+  // memory allocator used by Skia benefit from it.
+  const char *device_extensions[] = {
+      VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME,
+  };
+  GrVkExtensions vk_extensions;
+  vk_extensions.init(backend_context.fGetProc, backend_context.fInstance,
+                     backend_context.fPhysicalDevice, 0, nullptr,
+                     countof(device_extensions), device_extensions);
+  backend_context.fVkExtensions = &vk_extensions;
 
   context_ = GrContext::MakeVulkan(backend_context);
 

vulkan/vulkan_device.cc

@@ -68,6 +68,7 @@ VulkanDevice::VulkanDevice(VulkanProcTable& p_vk,
     VK_FUCHSIA_EXTERNAL_MEMORY_EXTENSION_NAME,
     VK_KHR_EXTERNAL_SEMAPHORE_EXTENSION_NAME,
     VK_FUCHSIA_EXTERNAL_SEMAPHORE_EXTENSION_NAME,
+    VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME,
 #endif
   };