Fix padding of a11y keyboard indicator when shelf is vertically aligned.

ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc

Index: ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
diff --git a/ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc b/ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
index 63eadf15bd9cc6aeeabf12619078ceae386b492d..2dadd1f34715c703e9439d802284e69f09be89ca 100644
--- a/ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
+++ b/ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
@@ -4,6 +4,7 @@
 
 #include "ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.h"
 
+#include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_constants.h"
 #include "ash/shell.h"
 #include "ash/system/status_area_widget.h"
@@ -44,7 +45,11 @@ VirtualKeyboardButton::~VirtualKeyboardButton() {
 gfx::Size VirtualKeyboardButton::GetPreferredSize() const {
   const int virtual_keyboard_button_height = kShelfSize;
   gfx::Size size = ImageButton::GetPreferredSize();
-  int padding = virtual_keyboard_button_height - size.height();
+  Shelf* shelf = Shelf::ForPrimaryDisplay();
+  bool is_horizontal = shelf && (shelf->alignment() == SHELF_ALIGNMENT_BOTTOM ||
+      shelf->alignment() == SHELF_ALIGNMENT_TOP);
+  int padding = is_horizontal ? virtual_keyboard_button_height - size.height() :
+      0;
   size.set_height(virtual_keyboard_button_height);
   size.set_width(size.width() + padding);
   return size;