Makes it easier to snap or dock windows near the edges when using touch

ash/wm/workspace/snap_sizer.h

 // Copyright (c) 2012 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.
 
 #ifndef ASH_WM_WORKSPACE_SNAP_SIZER_H_
 #define ASH_WM_WORKSPACE_SNAP_SIZER_H_
 
 #include <vector>
 
 #include "ash/ash_export.h"
@@ skipping 13 matching lines @@
 // The bounds used in this class are in the container's coordinates.
 class ASH_EXPORT SnapSizer {
  public:
   enum Edge {
     LEFT_EDGE,
     RIGHT_EDGE
   };
 
   enum InputType {
     TOUCH_MAXIMIZE_BUTTON_INPUT,
+    TOUCH_DRAG_INPUT,
     OTHER_INPUT
   };
 
+  // Snapping is made easier with a touch drag when using touchscreen.
+  static const int kScreenEdgeInsetForTouchDrag;
+
   // Set |input_type| to |TOUCH_MAXIMIZE_BUTTON_INPUT| when called by a touch
   // operation by the maximize button. This will allow the user to snap resize
   // the window beginning close to the border.
   SnapSizer(wm::WindowState* window_state,
             const gfx::Point& start,
             Edge edge,
             InputType input_type);
   virtual ~SnapSizer();
 
   // Snaps a window left or right.
@@ skipping 84 matching lines @@
   // sizer gets created.
   const std::vector<int> usable_width_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapSizer);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_SNAP_SIZER_H_