For some vector icons, get the size from the vector definition.

ash/frame/caption_buttons/frame_caption_button.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 "ash/frame/caption_buttons/frame_caption_button.h"
 
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/gfx/animation/throb_animation.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_palette.h"
@@ skipping 40 matching lines @@
   // horizontally symmetrical.
 }
 
 FrameCaptionButton::~FrameCaptionButton() {
 }
 
 void FrameCaptionButton::SetImage(CaptionButtonIcon icon,
                                   Animate animate,
                                   gfx::VectorIconId icon_image_id) {
   gfx::ImageSkia new_icon_image = gfx::CreateVectorIcon(
-      icon_image_id, 12,
-      use_light_images_ ? SK_ColorWHITE : gfx::kChromeIconGrey);
+      icon_image_id, use_light_images_ ? SK_ColorWHITE : gfx::kChromeIconGrey);
 
   // The early return is dependent on |animate| because callers use SetImage()
   // with ANIMATE_NO to progress the crossfade animation to the end.
   if (icon == icon_ &&
       (animate == ANIMATE_YES || !swap_images_animation_->is_animating()) &&
       new_icon_image.BackedBySameObjectAs(icon_image_)) {
     return;
   }
 
   if (animate == ANIMATE_YES)
@@ skipping 111 matching lines @@
 
   SkPaint paint;
   paint.setAlpha(alpha);
   canvas->DrawImageInt(to_center,
                        (width() - to_center.width()) / 2,
                        (height() - to_center.height()) / 2,
                        paint);
 }
 
 }  // namespace ash