Mac App Launcher is positioned on center of dock in certain cases.

chrome/browser/ui/app_list/app_list_positioner.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/app_list/app_list_positioner.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "ui/gfx/point.h"
@@ skipping 63 matching lines @@
     case SCREEN_EDGE_BOTTOM:
       anchor = gfx::Point(screen_rect.x(), work_area.bottom());
       break;
     default:
       NOTREACHED();
       anchor = gfx::Point();
   }
   return ClampAnchorPoint(anchor);
 }
 
+gfx::Point AppListPositioner::GetAnchorPointForShelfCenter(
+    ScreenEdge shelf_edge) const {
+  const gfx::Rect& work_area = display_.work_area();
+  gfx::Point anchor;
+  switch (shelf_edge) {
+    case SCREEN_EDGE_LEFT:
+      anchor =
+          gfx::Point(work_area.x(), work_area.y() + work_area.height() / 2);
+      break;
+    case SCREEN_EDGE_RIGHT:
+      anchor =
+          gfx::Point(work_area.right(), work_area.y() + work_area.height() / 2);
+      break;
+    case SCREEN_EDGE_TOP:
+      anchor = gfx::Point(work_area.x() + work_area.width() / 2, work_area.y());
+      break;
+    case SCREEN_EDGE_BOTTOM:
+      anchor =
+          gfx::Point(work_area.x() + work_area.width() / 2, work_area.bottom());
+      break;
+    default:
+      NOTREACHED();
+      anchor = gfx::Point();
+  }
+  return ClampAnchorPoint(anchor);
+}
+
 gfx::Point AppListPositioner::GetAnchorPointForShelfCursor(
     ScreenEdge shelf_edge,
     const gfx::Point& cursor) const {
   const gfx::Rect& work_area = display_.work_area();
   gfx::Point anchor;
   switch (shelf_edge) {
     case SCREEN_EDGE_LEFT:
       anchor = gfx::Point(work_area.x(), cursor.y());
       break;
     case SCREEN_EDGE_RIGHT:
@@ skipping 70 matching lines @@
 
   // Anchor the center of the window in a region that prevents the window
   // showing outside of the work area.
   bounds_rect.Inset(window_size_.width() / 2 + min_distance_from_edge_,
                     window_size_.height() / 2 + min_distance_from_edge_);
 
   anchor.SetToMax(bounds_rect.origin());
   anchor.SetToMin(bounds_rect.bottom_right());
   return anchor;
 }