Stubbed implementation of VK_GOOGLE_display_timing extension.

This provides the header changes and most of the "boilerplate" changes to add
the VK_GOOGLE_display_timing extension to Vulkan.  Future changes will modify
and integrate with the Surface, FrameEvents, and SurfaceFlinger code.

Test: Manually tested that existing apps won't tickle the new-extension paths.

Change-Id: Iec46b1cab4b2561702ebac9a4ae7587584793192
diff --git a/vulkan/libvulkan/code-generator.tmpl b/vulkan/libvulkan/code-generator.tmpl
index b27b36c..2c70d46 100644
--- a/vulkan/libvulkan/code-generator.tmpl
+++ b/vulkan/libvulkan/code-generator.tmpl
@@ -700,6 +700,8 @@
 VK_KHR_incremental_present
 VK_KHR_surface
 VK_KHR_swapchain
+VK_KHR_incremental_present
+VK_GOOGLE_display_timing
 {{end}}
 
 
@@ -1147,6 +1149,7 @@
   {{else if eq $ext "VK_KHR_swapchain"}}true
   {{else if eq $ext "VK_KHR_android_surface"}}true
   {{else if eq $ext "VK_KHR_incremental_present"}}true
+  {{else if eq $ext "VK_GOOGLE_display_timing"}}true
   {{end}}
 {{end}}