Add a version of gpu_fuzzer that is backed by the NULL ANGLE backend

ui/gl/gl_surface_egl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/gl_surface_egl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
@@ skipping 130 matching lines @@
 
   display_attribs.push_back(EGL_PLATFORM_ANGLE_TYPE_ANGLE);
   display_attribs.push_back(platform_type);
 
   if (warpDevice) {
     display_attribs.push_back(EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE);
     display_attribs.push_back(EGL_PLATFORM_ANGLE_DEVICE_TYPE_WARP_ANGLE);
   }
 
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
-  Visual* visual;
-  ui::XVisualManager::GetInstance()->ChooseVisualForWindow(
-      true, &visual, nullptr, nullptr, nullptr);
-  display_attribs.push_back(EGL_X11_VISUAL_ID_ANGLE);
-  display_attribs.push_back(static_cast<EGLint>(XVisualIDFromVisual(visual)));
+  // ANGLE_NULL doesn't use the visual, and may run without X11 where we can't
+  // get it anyway.
+  if (platform_type != EGL_PLATFORM_ANGLE_TYPE_NULL_ANGLE) {
+    Visual* visual;
+    ui::XVisualManager::GetInstance()->ChooseVisualForWindow(
+        true, &visual, nullptr, nullptr, nullptr);
+    display_attribs.push_back(EGL_X11_VISUAL_ID_ANGLE);
+    display_attribs.push_back(static_cast<EGLint>(XVisualIDFromVisual(visual)));
+  }
 #endif
 
   display_attribs.push_back(EGL_NONE);
 
   return eglGetPlatformDisplayEXT(EGL_PLATFORM_ANGLE_ANGLE,
                                   reinterpret_cast<void*>(native_display),
                                   &display_attribs[0]);
 }
 
 EGLDisplay GetDisplayFromType(DisplayType display_type,
@@ skipping 70 matching lines @@
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableES3GLContext)) {
     renderable_types.push_back(EGL_OPENGL_ES3_BIT);
   }
   renderable_types.push_back(EGL_OPENGL_ES2_BIT);
 
   EGLint buffer_size = 32;
   EGLint alpha_size = 8;
 
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
-  ui::XVisualManager::GetInstance()->ChooseVisualForWindow(
-      true, nullptr, &buffer_size, nullptr, nullptr);
-  alpha_size = buffer_size == 32 ? 8 : 0;
+  // If we're using ANGLE_NULL, we may not have a display, in which case we
+  // can't use XVisualManager.
+  if (g_native_display) {
+    ui::XVisualManager::GetInstance()->ChooseVisualForWindow(
+        true, nullptr, &buffer_size, nullptr, nullptr);
+    alpha_size = buffer_size == 32 ? 8 : 0;
+  }
 #endif
 
   EGLint surface_type = (format == GLSurface::SURFACE_SURFACELESS)
                             ? EGL_DONT_CARE
                             : EGL_WINDOW_BIT | EGL_PBUFFER_BIT;
 
   for (auto renderable_type : renderable_types) {
     EGLint config_attribs_8888[] = {EGL_BUFFER_SIZE,
                                     buffer_size,
                                     EGL_ALPHA_SIZE,
@@ skipping 957 matching lines @@
 }
 
 void* SurfacelessEGL::GetShareHandle() {
   return NULL;
 }
 
 SurfacelessEGL::~SurfacelessEGL() {
 }
 
 }  // namespace gl