Remove docked windows entirely in M59.

ash/common/wm/dock/dock_types.h

Index: ash/common/wm/dock/dock_types.h
diff --git a/ash/common/wm/dock/dock_types.h b/ash/common/wm/dock/dock_types.h
deleted file mode 100644
index 02e8b45027a3d1f1805588fd7c4ec88f1ab2c504..0000000000000000000000000000000000000000
--- a/ash/common/wm/dock/dock_types.h
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright (c) 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.
-
-#ifndef ASH_COMMON_WM_DOCK_DOCK_TYPES_H_
-#define ASH_COMMON_WM_DOCK_DOCK_TYPES_H_
-
-namespace ash {
-
-// Possible values of which side of the screen the windows are docked at.
-// This is used by DockedwindowLayoutManager and DockedWindowResizer to
-// implement docking behavior including magnetism while dragging windows into
-// or out of the docked windows area.
-enum DockedAlignment {
-  // No docked windows.
-  DOCKED_ALIGNMENT_NONE,
-
-  // Some windows are already docked on the left side of the screen.
-  DOCKED_ALIGNMENT_LEFT,
-
-  // Some windows are already docked on the right side of the screen.
-  DOCKED_ALIGNMENT_RIGHT,
-};
-
-// User action recorded for use in UMA histograms.

[varkha, 2017/02/28 00:59:02]

It may be possible to remove all "Ash.Dock.*" histograms now. See
https://codereview.chromium.org/45343003/diff/510001/tools/metrics/histograms...
for what can be removed.

[afakhry, 2017/03/09 22:28:26]

From what I understand, histogram.xml should not be changed even if we remove
the histograms themselves. The entires in histograms.xml are still needed to
decode histograms from previous versions.

-enum DockedAction {
-  DOCKED_ACTION_NONE,      // Regular drag of undocked window. Not recorded.
-  DOCKED_ACTION_DOCK,      // Dragged and docked a window.
-  DOCKED_ACTION_UNDOCK,    // Dragged and undocked a window.
-  DOCKED_ACTION_RESIZE,    // Resized a docked window.
-  DOCKED_ACTION_REORDER,   // Possibly reordered docked windows.
-  DOCKED_ACTION_EVICT,     // A docked window could not stay docked.
-  DOCKED_ACTION_MAXIMIZE,  // Maximized a docked window.
-  DOCKED_ACTION_MINIMIZE,  // Minimized a docked window.
-  DOCKED_ACTION_RESTORE,   // Restored a docked window that was minimized.
-  DOCKED_ACTION_CLOSE,     // Closed a window while it was docked.
-  DOCKED_ACTION_COUNT,     // Maximum value of this enum for histograms use.
-};
-
-// Event source for the docking user action (when known).
-enum DockedActionSource {
-  DOCKED_ACTION_SOURCE_UNKNOWN,
-  DOCKED_ACTION_SOURCE_MOUSE,
-  DOCKED_ACTION_SOURCE_TOUCH,
-  DOCKED_ACTION_SOURCE_KEYBOARD,
-
-  // Maximum value of this enum for histograms use.
-  DOCKED_ACTION_SOURCE_COUNT,
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_WM_DOCK_DOCK_TYPES_H_