Implement a runtime headless mode for Linux

content/browser/browser_main_loop.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 "content/browser/browser_main_loop.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 376 matching lines @@
   explicit GpuDataManagerVisualProxy(GpuDataManagerImpl* gpu_data_manager)
       : gpu_data_manager_(gpu_data_manager) {
     gpu_data_manager_->AddObserver(this);
   }
 
   ~GpuDataManagerVisualProxy() override {
     gpu_data_manager_->RemoveObserver(this);
   }
 
   void OnGpuInfoUpdate() override {
+    if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kHeadless))
+      return;
     gpu::GPUInfo gpu_info = gpu_data_manager_->GetGPUInfo();
     if (!ui::XVisualManager::GetInstance()->OnGPUInfoChanged(
             gpu_info.software_rendering ||
                 !gpu_data_manager_->GpuAccessAllowed(nullptr),
             gpu_info.system_visual, gpu_info.rgba_visual)) {
       // The GPU process sent back bad visuals, which should never happen.
       auto* gpu_process_host = GpuProcessHost::Get(
           GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED, false);
       if (gpu_process_host)
         gpu_process_host->ForceShutdown();
@@ skipping 1065 matching lines @@
   INITCOMMONCONTROLSEX config;
   config.dwSize = sizeof(config);
   config.dwICC = ICC_WIN95_CLASSES;
   if (!InitCommonControlsEx(&config))
     PLOG(FATAL);
 #endif
 
 #if defined(USE_AURA)
 
 #if defined(USE_X11)
-  if (!gfx::GetXDisplay()) {
+  if (!parsed_command_line_.HasSwitch(switches::kHeadless) &&
+      !gfx::GetXDisplay()) {
     LOG(ERROR) << "Unable to open X display.";
     return false;
   }
 #endif
 
   // Env creates the compositor. Aura widgets need the compositor to be created
   // before they can be initialized by the browser.
   env_ = aura::Env::CreateInstance();
 #endif  // defined(USE_AURA)
 
@@ skipping 133 matching lines @@
     scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner =
         audio_thread_->task_runner();
     audio_manager_ = media::AudioManager::Create(std::move(audio_task_runner),
                                                  std::move(worker_task_runner),
                                                  MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 }
 
 }  // namespace content