Implemented prototype for new ink drop specs.

chrome/browser/ui/views/toolbar/back_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 "chrome/browser/ui/views/toolbar/back_button.h"
 
 #include "ui/gfx/geometry/insets.h"
 #include "ui/views/animation/ink_drop_animation_controller.h"
 #include "ui/views/controls/button/label_button_border.h"
 #include "ui/views/painter.h"
@@ skipping 15 matching lines @@
   // probably a FocusBorder constant.
   const int kFocusRectInset = 3;
   SetFocusPainter(views::Painter::CreateDashedFocusPainterWithInsets(
                       gfx::Insets(kFocusRectInset, kFocusRectInset + margin,
                                   kFocusRectInset, kFocusRectInset)));
 
   InvalidateLayout();
 }
 
 void BackButton::LayoutInkDrop() {
-  ink_drop_animation_controller()->SetInkDropBounds(
-      gfx::Rect(margin_leading_, 0, width() - margin_leading_, height()));
+  ToolbarButton::LayoutInkDrop();
+  gfx::Size ink_drop_size =
+      ink_drop_animation_controller()->GetInkDropLargeSize();
+  ink_drop_animation_controller()->SetInkDropOrigin(gfx::Point(
+      margin_leading_ + (width() - margin_leading_ - ink_drop_size.width()) / 2,
+      (height() - ink_drop_size.height()) / 2));
 }
 
 const char* BackButton::GetClassName() const {
   return "BackButton";
 }
 
 scoped_ptr<views::LabelButtonBorder> BackButton::CreateDefaultBorder() const {
   scoped_ptr<views::LabelButtonBorder> border =
       ToolbarButton::CreateDefaultBorder();
 
   // Adjust border insets to follow the margin change,
   // which will be reflected in where the border is painted
   // through |GetThemePaintRect|.
   const gfx::Insets insets(border->GetInsets());
   border->set_insets(gfx::Insets(insets.top(), insets.left() + margin_leading_,
                                  insets.bottom(), insets.right()));
 
   return border.Pass();
 }
 
 gfx::Rect BackButton::GetThemePaintRect() const  {
   gfx::Rect rect(LabelButton::GetThemePaintRect());
   rect.Inset(margin_leading_, 0, 0, 0);
   return rect;
 }