Adjusts dragging logic to be less likely to trigger false positive switch from snapping to docking

ash/wm/workspace/workspace_window_resizer.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_WINDOW_RESIZER_H_
 #define ASH_WM_WORKSPACE_WINDOW_RESIZER_H_
 
 #include <vector>
 
 #include "ash/wm/window_resizer.h"
 #include "ash/wm/workspace/magnetism_matcher.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/aura/window_tracker.h"
 
 namespace ash {
 class DockedWindowLayoutManager;
 class PhantomWindowController;
 class TwoStepEdgeCycler;
 class WindowSize;
 
 namespace wm {
 class WindowState;
 }
 
+// The edge to which the window should be snapped at the end of the drag.
+enum SnapType { SNAP_LEFT, SNAP_RIGHT, SNAP_NONE };
+
 // WindowResizer implementation for workspaces. This enforces that windows are
 // not allowed to vertically move or resize outside of the work area. As windows
 // are moved outside the work area they are shrunk. We remember the height of
 // the window before it was moved so that if the window is again moved up we
 // attempt to restore the old height.
 class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
  public:
   // When dragging an attached window this is the min size we'll make sure is
   // visible. In the vertical direction we take the max of this and that from
   // the delegate.
@@ skipping 22 matching lines @@
   void CompleteDrag() override;
   void RevertDrag() override;
 
  private:
   WorkspaceWindowResizer(wm::WindowState* window_state,
                          const std::vector<aura::Window*>& attached_windows);
 
  private:
   friend class WorkspaceWindowResizerTest;
 
-  // The edge to which the window should be snapped at the end of the drag.
-  enum SnapType {
-    SNAP_LEFT,
-    SNAP_RIGHT,
-    SNAP_NONE
-  };
-
   // Lays out the attached windows. |bounds| is the bounds of the main window.
   void LayoutAttachedWindows(gfx::Rect* bounds);
 
   // Calculates the new sizes of the attached windows, given that the main
   // window has been resized (along the primary axis) by |delta|.
   // |available_size| is the maximum length of the space that the attached
   // windows are allowed to occupy (ie: the distance between the right/bottom
   // edge of the primary window and the right/bottom of the desktop area).
   // Populates |sizes| with the desired sizes of the attached windows, and
   // returns the number of pixels that couldn't be allocated to the attached
@@ skipping 135 matching lines @@
   // Used to determine if this has been deleted during a drag such as when a tab
   // gets dragged into another browser window.
   base::WeakPtrFactory<WorkspaceWindowResizer> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkspaceWindowResizer);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_WINDOW_RESIZER_H_