Re-layout Chrome OS audio row when headphone connected

ash/common/system/chromeos/audio/volume_view.cc

Index: ash/common/system/chromeos/audio/volume_view.cc
diff --git a/ash/common/system/chromeos/audio/volume_view.cc b/ash/common/system/chromeos/audio/volume_view.cc
index 30ed63db42e22d847cd746d9be5621ad1f6d2cff..22132d96465da226d8a9f44ae993a181dcd03c4d 100644
--- a/ash/common/system/chromeos/audio/volume_view.cc
+++ b/ash/common/system/chromeos/audio/volume_view.cc
@@ -256,6 +256,8 @@ void VolumeView::UpdateDeviceTypeAndMore() {
   if (!show_more)
     return;
 
+  bool was_visible = device_type_->visible();
+
   // Show output device icon if necessary.
   device_type_->SetVisible(false);
   if (MaterialDesignController::IsSystemTrayMenuMaterial()) {
@@ -275,6 +277,8 @@ void VolumeView::UpdateDeviceTypeAndMore() {
       device_type_->SetVisible(true);
     }
   }
+  if (device_type_->visible() != was_visible)
+    device_type_->InvalidateLayout();

[sadrul, 2017/02/02 21:25:34]

Setting the visibility can trigger a repaint. For example, if the View is
visible, then we mark it as hidden first (line 262 above), then make it visible
again. So although we don't actually need to repaint, we end up repainting
anyway.

May I suggest changing this code so this doesn't happen? For example:
  if (!show_more)
    return;
  bool should_be_visible = false;
  if (....) {
    ...
    should_be_visible = true;
  } else {
    ...
    should_be_visible = true;
  }
  if (should_be_visible != device_type_->visible()) {
    device_type_->SetVisible(should_be_visible);
    device_type_->InvalidateLayout();
  }


i.e. set the visibility only if we know that it needs to be changed.

[mohsen, 2017/02/02 21:35:31]

Sure. That makes a lot of sense. Done.

 }
 
 void VolumeView::HandleVolumeUp(int level) {