Remove Tabpose feature on mac, and supporting infrastructure (PaintAtSize)

content/public/browser/notification_types.h

Index: content/public/browser/notification_types.h
diff --git a/content/public/browser/notification_types.h b/content/public/browser/notification_types.h
index 3366f169cb43b3a1aa3ce320e6283bf3abe53613..a2849893f5e4c1957968f6e2205f86c050759599 100644
--- a/content/public/browser/notification_types.h
+++ b/content/public/browser/notification_types.h
@@ -179,11 +179,6 @@ enum NotificationType {
   // painted. The source is the RenderWidgetHost, the details are not used.
   NOTIFICATION_RENDER_WIDGET_HOST_DID_UPDATE_BACKING_STORE,
 
-  // This notifies the observer that a PaintAtSizeACK was received. The source
-  // is the RenderWidgetHost, the details are an instance of
-  // std::pair<int, gfx::Size>.
-  NOTIFICATION_RENDER_WIDGET_HOST_DID_RECEIVE_PAINT_AT_SIZE_ACK,
-
   // This notifies the observer that a HandleInputEventACK was received. The
   // source is the RenderWidgetHost, the details are the type of event
   // received.