Add support for EXT_image_flush_external extension

third_party/khronos/EGL/eglext.h

Index: third_party/khronos/EGL/eglext.h
diff --git a/third_party/khronos/EGL/eglext.h b/third_party/khronos/EGL/eglext.h
index b476dc59057f578d40a78cf4f904865f3c857241..831e3d8b1b9aa95795f7a50f4bd4af72873cac4f 100644
--- a/third_party/khronos/EGL/eglext.h
+++ b/third_party/khronos/EGL/eglext.h
@@ -574,6 +574,18 @@ typedef EGLint (EGLAPIENTRYP PFNEGLDUPNATIVEFENCEFDANDROIDPROC)(EGLDisplay dpy,
 #define EGL_SYNC_PRIOR_COMMANDS_IMPLICIT_EXTERNAL_ARM 0x328A
 #endif /* EGL_ARM_implicit_external_sync */
 
+
+#ifndef EGL_EXT_image_flush_external
+#define EGL_EXT_image_flush_external 1
+#define EGL_IMAGE_EXTERNAL_TARGET_NVX	0x3330
+#define EGL_DECOMPRESSED_NVX		0x3331
+#ifdef EGL_EGLEXT_PROTOTYPES
+EGLAPI EGLBoolean EGLAPIENTRY eglImageFlushExternalEXT(EGLDisplay dpy, EGLImageKHR image, const EGLint *attrib_list);
+#else
+typedef EGLBoolean (EGLAPIENTRYP PFNGLEGLIMAGEFLUSHEXTERNALEXT) (EGLDisplay dpy, EGLImageKHR image, const EGLint *attrib_list);
+#endif
+#endif
+
 #ifdef __cplusplus
 }
 #endif