ozone: Add atomic initialization path

chrome/browser/chromeos/login/chrome_restart_request.cc

 // Copyright 2013 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 "chrome/browser/chromeos/login/chrome_restart_request.h"
 
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "base/command_line.h"
@@ skipping 150 matching lines @@
     ::switches::kDisableWebRtcHWDecoding,
     ::switches::kDisableWebRtcHWEncoding,
     ::switches::kEnableWebRtcHWH264Encoding,
 #endif
     ::switches::kDisableVaapiAcceleratedVideoEncode,
 #if defined(USE_OZONE)
     ::switches::kOzoneInitialDisplayBounds,
     ::switches::kOzoneInitialDisplayPhysicalSizeMm,
     ::switches::kOzonePlatform,
     ::switches::kOzoneUseSurfaceless,
+    ::switches::kOzoneUseAtomicDrm,

[dnicoara, 2015/05/19 17:13:14]

This is a platform specific flag. I know that this adds limitations but, I don't
think we want to start adding platform specific flags outside the platform.

[achaulk, 2015/05/19 17:15:44]

The other option is to add a new platform drm_atomic

[dnicoara, 2015/05/19 17:21:58]

Well, we could just make it a compile time flag. I know that having it as a flag
will make it easier to switch between the two during initial
development/debugging, but other than that we expect to just move towards the
atomic API and even deprecate the old path if possible.

[achaulk, 2015/05/19 17:27:36]

Yeah, at which point we rip out the flag. The goal is to make it so you don't
need a custom build to use this path, which means compile time isn't necessarily
enough

[dnicoara, 2015/05/19 17:54:06]

I still don't see much value outside your development workflow, but I do see
this creating precedent on sprinkling platform specific flags outside the
platform code.

Lets proceed with relying on USE_DRM_ATOMIC and drmSetClientCap() to enable
atomic.

 #endif
     app_list::switches::kDisableSyncAppList,
     app_list::switches::kEnableSyncAppList,
     ash::switches::kAshHostWindowBounds,
     ash::switches::kAshTouchHud,
     ash::switches::kAuraLegacyPowerButton,
     chromeos::switches::kDefaultWallpaperLarge,
     chromeos::switches::kDefaultWallpaperSmall,
     chromeos::switches::kGuestWallpaperLarge,
     chromeos::switches::kGuestWallpaperSmall,
@@ skipping 194 matching lines @@
     // Relaunch chrome without session manager on dev box.
     ReLaunch(command_line);
     return;
   }
 
   // ChromeRestartRequest deletes itself after request sent to session manager.
   (new ChromeRestartRequest(command_line))->Start();
 }
 
 }  // namespace chromeos