Add --headless flag to Windows

chrome/app/chrome_main.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 <stdint.h>
 
 #include "base/command_line.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/app/chrome_main_delegate.h"
@@ skipping 75 matching lines @@
   // have the same version.
   if (install_static::InstallDetails::Get().VersionMismatch())
     base::debug::DumpWithoutCrashing();
 #else
   params.argc = argc;
   params.argv = argv;
 #endif
 
 #if !defined(OS_WIN)
   base::CommandLine::Init(params.argc, params.argv);
+#else
+  base::CommandLine::Init(0, NULL);

[sky, 2017/03/22 16:05:03]

Why do you have to add this? Aren't we already init'ing the command line?
Assuming you need this, NULL -> nullptr and move this to be between 88/89 and
line 95 to between 91/92.

[dvallet, 2017/03/27 05:59:50]

Done. You are right, it's not needed.
I've moved the initialization of Linux to 91/92 

+#endif
   const base::CommandLine* command_line(base::CommandLine::ForCurrentProcess());
   ALLOW_UNUSED_LOCAL(command_line);
-#endif
 
-#if defined(OS_LINUX) || defined(OS_MACOSX)
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
   if (command_line->HasSwitch(switches::kHeadless)) {
 #if defined(OS_MACOSX)
     SetUpBundleOverrides();
 #endif
+#if defined(OS_WIN)
+    return headless::HeadlessShellMain(instance, sandbox_info);
+#else
     return headless::HeadlessShellMain(argc, argv);

[sky, 2017/03/22 16:05:03]

Can HeadlessShellMain take ContentMainParams so that you don't need all the
ifdefs here?

[Sami, 2017/03/22 19:46:25]

We could add an override for that, but for users who embed the library we should
also keep the old entrypoint for compatibility.

[dvallet, 2017/03/27 05:59:50]

Done

+#endif
   }
-#endif  // defined(OS_LINUX) || defined(OS_MACOSX)
+#endif  // defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
 
 #if BUILDFLAG(ENABLE_PACKAGE_MASH_SERVICES)
   version_info::Channel channel = chrome::GetChannel();
   if (channel == version_info::Channel::CANARY ||
       channel == version_info::Channel::UNKNOWN) {
     if (command_line->HasSwitch(switches::kMash))
       return MashMain();
     WaitForMashDebuggerIfNecessary();
     if (service_manager::ServiceManagerIsRemote())
       params.env_mode = aura::Env::Mode::MUS;
   }
 #endif  // BUILDFLAG(ENABLE_PACKAGE_MASH_SERVICES)
 
   int rv = content::ContentMain(params);
 
 #if defined(OS_WIN)
   base::win::SetShouldCrashOnProcessDetach(false);
 #endif
 
   return rv;
 }