EGL: Implement EGL_KHR_surfaceless_context

Add extension string to registry
Add extension flag to EGL and Vulkan Displays

Bug: angleproject:3960
Test: dEQP-EGL.functional.surfaceless_context.*
      angle_end2end_tests --gtest_filter=EGLSurfacelessContextTest*
Change-Id: Id17916f1f636454af395b7bc92892dcf8fc93e54
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1885075
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

scripts/code_generation_hashes/GL_EGL_WGL_loader.json

@@ -6,7 +6,7 @@
   "scripts/generate_loader.py":
     "48c60c668bec42a80378179aae2acc61",
   "scripts/registry_xml.py":
-    "c633c0b4490ef4ab5aaebb295510398d",
+    "fad2f8068a585ee2e6a66dd604fe93e1",
   "scripts/wgl.xml":
     "aa96419c582af2f6673430e2847693f4",
   "src/libEGL/egl_loader_autogen.cpp":

scripts/code_generation_hashes/GL_EGL_entry_points.json

@@ -12,7 +12,7 @@
   "scripts/gl_angle_ext.xml":
     "d6907cd84d95ac0b32a164194eadcf53",
   "scripts/registry_xml.py":
-    "c633c0b4490ef4ab5aaebb295510398d",
+    "fad2f8068a585ee2e6a66dd604fe93e1",
   "scripts/wgl.xml":
     "aa96419c582af2f6673430e2847693f4",
   "src/libANGLE/Context_gl_1_0_autogen.h":

scripts/code_generation_hashes/GLenum_value_to_string_map.json

@@ -6,7 +6,7 @@
   "scripts/gl_angle_ext.xml":
     "d6907cd84d95ac0b32a164194eadcf53",
   "scripts/registry_xml.py":
-    "c633c0b4490ef4ab5aaebb295510398d",
+    "fad2f8068a585ee2e6a66dd604fe93e1",
   "src/libANGLE/gl_enum_utils_autogen.cpp":
     "3178466fb9ef26a3349fe59a76295dc3",
   "src/libANGLE/gl_enum_utils_autogen.h":

scripts/code_generation_hashes/proc_table.json

@@ -10,7 +10,7 @@
   "scripts/gl_angle_ext.xml":
     "d6907cd84d95ac0b32a164194eadcf53",
   "scripts/registry_xml.py":
-    "c633c0b4490ef4ab5aaebb295510398d",
+    "fad2f8068a585ee2e6a66dd604fe93e1",
   "scripts/wgl.xml":
     "aa96419c582af2f6673430e2847693f4",
   "src/libGL/proc_table_wgl_autogen.cpp":

scripts/registry_xml.py

@@ -118,6 +118,7 @@ supported_egl_extensions = [
     "EGL_KHR_no_config_context",
     "EGL_KHR_stream",
     "EGL_KHR_stream_consumer_gltexture",
+    "EGL_KHR_surfaceless_context",
     "EGL_KHR_swap_buffers_with_damage",
     "EGL_KHR_wait_sync",
     "EGL_NV_post_sub_buffer",

src/libANGLE/renderer/vulkan/DisplayVk.cpp

@@ -189,6 +189,7 @@ void DisplayVk::generateExtensions(egl::DisplayExtensions *outExtensions) const
     outExtensions->glRenderbufferImage   = true;
     outExtensions->imageNativeBuffer =
         getRenderer()->getFeatures().supportsAndroidHardwareBuffer.enabled;
+    outExtensions->surfacelessContext = true;
 
     outExtensions->noConfigContext = true;
 }