Flip the left/right speaker when the device is in yoga mode.

ash/display/display_manager.cc

Index: ash/display/display_manager.cc
diff --git a/ash/display/display_manager.cc b/ash/display/display_manager.cc
index 4cec2ea81d73a1332c309e16efe78eb081f4ce7c..016feda0c1d4c791c8432c68c4032d206478ea1b 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -39,6 +39,7 @@
 #if defined(OS_CHROMEOS)
 #include "ash/display/display_configurator_animation.h"
 #include "base/sys_info.h"
+#include "chromeos/audio/cras_audio_handler.h"
 #endif
 
 #if defined(OS_WIN)
@@ -437,6 +438,12 @@ void DisplayManager::SetDisplayRotation(int64 display_id,
   }
   AddMirrorDisplayInfoIfAny(&display_info_list);
   UpdateDisplays(display_info_list);
+
+#if defined(OS_CHROMEOS)
+  // Swap the left/right channel of the speaker only if it is yoga mode.

[oshima, 2014/09/30 22:29:53]

1) Can you use gfx::DisplayObserver::OnDisplayMetricsChanged?

2) You need to check if the display is for internal display as you can rotate
external display.

3) You can rotate display on any display, so this happens when a user rotate
screen 180 on any chromebook. Is this ok?

[jennyz, 2014/10/01 00:22:59]

Thanks for pointing me to gfx::DisplayObserver::OnDisplayMetricsChanged, this
makes the code much easier and clean.
I think it is ok to swap the audio channel when the display is rotated, which is
a rare case for user anyway.

+  chromeos::CrasAudioHandler::Get()->SwapLeftRight(rotation ==
+                                                   gfx::Display::ROTATE_180);
+#endif
 }
 
 void DisplayManager::SetDisplayUIScale(int64 display_id,