Revert "Temporarily disable enumeration of VK_KHR_incremental_present"

This reverts commit 15b1cb2e57435514b4810f27e5ee01a2e480b338.

Change-Id: Ia4d6a75a6fc71107145e7273e891e1efb0f3eb9a
diff --git a/vulkan/libvulkan/driver.cpp b/vulkan/libvulkan/driver.cpp
index a23056c..32f777d 100644
--- a/vulkan/libvulkan/driver.cpp
+++ b/vulkan/libvulkan/driver.cpp
@@ -739,10 +739,8 @@
     const InstanceData& data = GetData(physicalDevice);
     static const std::array<VkExtensionProperties, 2> loader_extensions = {{
         // WSI extensions
-#if 0 // Remove this "#if 0" once the VK_KHR_incremental_present extension is ratified
         {VK_KHR_INCREMENTAL_PRESENT_EXTENSION_NAME,
          VK_KHR_INCREMENTAL_PRESENT_SPEC_VERSION},
-#endif
         {VK_GOOGLE_DISPLAY_TIMING_EXTENSION_NAME,
          VK_GOOGLE_DISPLAY_TIMING_SPEC_VERSION},
     }};