Implement a runtime headless mode for Linux

ui/gl/init/gl_initializer_x11.cc

 // Copyright 2016 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/init/gl_initializer.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
+#include "ui/gfx/switches.h"
 #include "ui/gfx/x/x11_types.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_egl_api_implementation.h"
 #include "ui/gl/gl_gl_api_implementation.h"
 #include "ui/gl/gl_glx_api_implementation.h"
 #include "ui/gl/gl_implementation_osmesa.h"
 #include "ui/gl/gl_osmesa_api_implementation.h"
 #include "ui/gl/gl_surface_egl.h"
 #include "ui/gl/gl_surface_glx.h"
 #include "ui/gl/gl_surface_osmesa_x11.h"
@@ skipping 95 matching lines @@
 
   InitializeStaticGLBindingsGL();
   InitializeStaticGLBindingsEGL();
 
   return true;
 }
 
 }  // namespace
 
 bool InitializeGLOneOffPlatform() {
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kHeadless))
+    return true;
+
   switch (GetGLImplementation()) {
     case kGLImplementationDesktopGL:
       if (!GLSurfaceGLX::InitializeOneOff()) {
         LOG(ERROR) << "GLSurfaceGLX::InitializeOneOff failed.";
         return false;
       }
       return true;
     case kGLImplementationOSMesaGL:
       if (!GLSurfaceOSMesaX11::InitializeOneOff()) {
         LOG(ERROR) << "GLSurfaceOSMesaX11::InitializeOneOff failed.";
@@ skipping 51 matching lines @@
 void ShutdownGLPlatform() {
   GLSurfaceEGL::ShutdownOneOff();
   ClearBindingsEGL();
   ClearBindingsGL();
   ClearBindingsGLX();
   ClearBindingsOSMESA();
 }
 
 }  // namespace init
 }  // namespace gl