command_buffer_gles2: Implement EGL default Display as a global object

gpu/gles2_conform_support/egl/test_support.h

Index: gpu/gles2_conform_support/egl/test_support.h
diff --git a/gpu/gles2_conform_support/egl/test_support.h b/gpu/gles2_conform_support/egl/test_support.h
index b1a70885bdcd7c58e0a3dbee3d58e022dd8ff421..f5cca7f53f65b53d7492788fea152f26c40699d1 100644
--- a/gpu/gles2_conform_support/egl/test_support.h
+++ b/gpu/gles2_conform_support/egl/test_support.h
@@ -5,6 +5,8 @@
 #ifndef GPU_GLES2_CONFORM_SUPPORT_EGL_TEST_SUPPORT_H_
 #define GPU_GLES2_CONFORM_SUPPORT_EGL_TEST_SUPPORT_H_
 
+#include <EGL/egl.h>
+
 #if defined(COMPONENT_BUILD) && defined(COMMAND_BUFFER_GLES_LIB_SUPPORT_ONLY)
 // A variable used for communicating whether the app has initialized the global
 // variables.
@@ -16,4 +18,15 @@
 EGLAPI extern EGLAPIENTRY bool g_command_buffer_gles_has_atexit_manager;
 #endif
 
+extern "C" {
+// A function to support GTF windowless tests. gles2_conform_test_windowless and
+// khronos_glcts_test_windowless create "windowless" native windows and render
+// to those. The test runners do not at the moment implement creating said
+// windowless native windows. This call sets the system so that it will create a
+// pbuffer when eglCreateWindow is called.
+EGLAPI EGLAPIENTRY void
+CommandBufferGLESSetNextCreateWindowSurfaceCreatesPBuffer(EGLDisplay eglDisplay,
+                                                          EGLint width,
+                                                          EGLint height);
+}
 #endif