Revert "Use DisplayVkSimple on ChromeOS"

This reverts commit b8ddba2a67.

Reason for revert: Breaks Chromium

Original change's description:
> Use DisplayVkSimple on ChromeOS
>
> Currently, we always use DisplayVkHeadless on ChromeOS which can fail
> if the drivers do not support VK_EXT_headless_surface (e.g. Intel).
> This CL changes the default to use DisplayVkSimple which requires
> VK_KHR_display which is better supported. At the end of the day, CrOS
> never really uses Vulkan WSI, so the actual WSI extension used
> doesn't matter.
>
> Bug: b/292249282
> Change-Id: I0f8cfafa635405850cda97c84ad45d3f6aec5103
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4727450
> Reviewed-by: Geoff Lang <geofflang@chromium.org>
> Commit-Queue: Brian Ho <hob@chromium.org>

Bug: b/292249282
Change-Id: If3ab1a39cb86dae1bf0652ca16bba323f497fcc4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4734578
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Yuxin Hu <yuxinhu@google.com>
Auto-Submit: Brian Ho <hob@chromium.org>
Commit-Queue: Yuxin Hu <yuxinhu@google.com>

gni/angle.gni

@@ -57,8 +57,7 @@ if (angle_has_build) {
     import("//build/config/win/visual_studio_version.gni")
   }
 
-  # Not all ChromeOS devices support VK_EXT_headless_surface.
-  if (is_castos || (ozone_platform_headless && !is_chromeos)) {
+  if (is_castos || ozone_platform_headless) {
     angle_vulkan_display_mode = "headless"
   }
 

src/libANGLE/Display.cpp

@@ -461,9 +461,10 @@ rx::DisplayImpl *CreateDisplayFromAttribs(EGLAttrib displayType,
             impl = new rx::DisplayWGL(state);
 #    elif defined(ANGLE_PLATFORM_LINUX)
 #        if defined(ANGLE_USE_GBM)
-            if (platformType == 0 || platformType == EGL_PLATFORM_VULKAN_DISPLAY_MODE_SIMPLE_ANGLE)
+            if (platformType == 0 ||
+                platformType == EGL_PLATFORM_VULKAN_DISPLAY_MODE_HEADLESS_ANGLE)
             {
-                // platformType == EGL_PLATFORM_VULKAN_DISPLAY_MODE_SIMPLE_ANGLE is a hack,
+                // platformType == EGL_PLATFORM_VULKAN_DISPLAY_MODE_HEADLESS_ANGLE is a hack,
                 // to allow ChromeOS GLES backend to continue functioning when Vulkan is enabled.
                 impl = new rx::DisplayEGL(state);
                 break;