[ash-md] Fix layout of launcher and overflow buttons in Ash MD shelf

ash/common/shelf/overflow_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/common/shelf/overflow_button.h"
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/ink_drop_button_listener.h"
 #include "ash/common/shelf/shelf_constants.h"
@@ skipping 154 matching lines @@
 
 int OverflowButton::NonMaterialBackgroundImageId() const {
   if (shelf_view_->IsShowingOverflowBubble())
     return IDR_AURA_NOTIFICATION_BACKGROUND_PRESSED;
   return IDR_AURA_NOTIFICATION_BACKGROUND_NORMAL;
 }
 
 gfx::Rect OverflowButton::CalculateButtonBounds() const {
   ShelfAlignment alignment = wm_shelf_->GetAlignment();
   gfx::Rect bounds(GetContentsBounds());
-  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   if (MaterialDesignController::IsShelfMaterial()) {
-    const int width_offset = (bounds.width() - kOverflowButtonSize) / 2;
-    const int height_offset = (bounds.height() - kOverflowButtonSize) / 2;
-    if (IsHorizontalAlignment(alignment)) {
-      bounds = gfx::Rect(bounds.x() + width_offset, bounds.y() + height_offset,
-                         kOverflowButtonSize, kOverflowButtonSize);
-    } else {
-      bounds = gfx::Rect(bounds.x() + height_offset, bounds.y() + width_offset,
-                         kOverflowButtonSize, kOverflowButtonSize);
-    }
+    // Align the button to the top of a bottom-aligned shelf, to the right edge
+    // a left-aligned shelf, and to the left edge of a right-aligned shelf.
+    const int inset = (GetShelfConstant(SHELF_SIZE) - kOverflowButtonSize) / 2;
+    const int x = alignment == SHELF_ALIGNMENT_LEFT
+                      ? bounds.right() - inset - kOverflowButtonSize
+                      : bounds.x() + inset;
+    bounds = gfx::Rect(x, bounds.y() + inset, kOverflowButtonSize,
+                       kOverflowButtonSize);
   } else {
+    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     const gfx::ImageSkia* background =
         rb.GetImageNamed(NonMaterialBackgroundImageId()).ToImageSkia();
     if (alignment == SHELF_ALIGNMENT_LEFT) {
       bounds =
           gfx::Rect(bounds.right() - background->width() - kShelfItemInset,
                     bounds.y() + (bounds.height() - background->height()) / 2,
                     background->width(), background->height());
     } else if (alignment == SHELF_ALIGNMENT_RIGHT) {
       bounds =
           gfx::Rect(bounds.x() + kShelfItemInset,
                     bounds.y() + (bounds.height() - background->height()) / 2,
                     background->width(), background->height());
     } else {
       bounds =
           gfx::Rect(bounds.x() + (bounds.width() - background->width()) / 2,
                     bounds.y() + kShelfItemInset, background->width(),
                     background->height());
     }
   }
   return bounds;
 }
 
 }  // namespace ash