Implement a runtime headless mode for Linux

content/browser/gpu/gpu_process_host.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/gpu/gpu_process_host.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 116 matching lines @@
     switches::kEnableHeapProfiling,
     switches::kEnableLogging,
 #if defined(OS_CHROMEOS)
     switches::kDisableVaapiAcceleratedVideoEncode,
 #endif
     switches::kGpuDriverBugWorkarounds,
     switches::kGpuStartupDialog,
     switches::kGpuSandboxAllowSysVShm,
     switches::kGpuSandboxFailuresFatal,
     switches::kGpuSandboxStartEarly,
+    switches::kHeadless,
     switches::kLoggingLevel,
     switches::kEnableLowEndDeviceMode,
     switches::kDisableLowEndDeviceMode,
     switches::kEnableMemoryBenchmarking,
     switches::kNoSandbox,
     switches::kProfilerTiming,
     switches::kTestGLLib,
     switches::kTraceConfigFile,
     switches::kTraceStartup,
     switches::kTraceToConsole,
@@ skipping 1044 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content