Remove implementation of Panels on OSes other than ChromeOS.

chrome/browser/ui/cocoa/panels/mouse_drag_controller.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 CHROME_BROWSER_UI_COCOA_PANELS_MOUSE_DRAG_CONTROLLER_H_
-#define CHROME_BROWSER_UI_COCOA_PANELS_MOUSE_DRAG_CONTROLLER_H_
-
-#import <Cocoa/Cocoa.h>
-
-// When Drag is cancelled by hitting ESC key, we may still receive
-// the mouseDragged events but should ignore them until the mouse button is
-// released. Use these simple states to track this condition.
-enum PanelDragState {
-  PANEL_DRAG_CAN_START,  // Mouse key went down, drag may be started.
-  PANEL_DRAG_IN_PROGRESS,
-  PANEL_DRAG_SUPPRESSED  // Ignore drag events until PANEL_DRAG_CAN_START.
-};
-
-@class MouseDragController;
-
-@protocol MouseDragControllerClient
-// Called on initial mouseDown. Followed by dragStarted/dragProgress/dragEnded
-// (which can be skipped if the drag didn't start) and then by cleanupAfterDrag.
-- (void)prepareForDrag;
-
-// Called wehen drag threshold was exceeded and actual drag should start.
-// Note that the drag is processed using a local nested message loop.
-// |initialMouseLocation| is in containing NSWindow's coordinates.
-- (void)dragStarted:(NSPoint)initialMouseLocation;
-
-// Called 0 to multiple times between dragStarted and dragEnded, to report
-// current mouse location. |mouseLocation| is in window coordinates.
-- (void)dragProgress:(NSPoint)mouseLocation;
-
-- (void)dragEnded:(BOOL)cancelled;
-
-// Always complements prepareForDrag. Clients which create a MouseDragController
-// in their mouseDown may release it in this method.
-- (void)cleanupAfterDrag;
-@end
-
-// This class encapsulates the mouse drag start/progress/termination logic,
-// including having a threashold before actually starting a drag and termination
-// of the drag on ESC, mouseUp and other operations. It also hosts the nested
-// message loop that is used during the drag operation.
-//
-// The client of the controller should be a NSView implementing
-// MouseDragControllerClient protocol. The client simply delegates mouse events
-// to the controller, and controller invokes higher-level
-// dragStarted/dragProgress/dragEnded callbacks on the client.
-// The controller can be created in initial mouseDown and then released in the
-// cleanupAfterDrag callback, or it can be preallocated and used across multiple
-// drag operations.
-//
-// The pattern of usage:
-// Lets say MyView is a NSView <MouseDragControllerClient>
-//
-// First, create an instance of MouseDragController and init it:
-//     dragController_.reset([[MouseDragController alloc] initWithClient:self]);
-// then delegate mouse messages to it:
-//
-// - (void)mouseDown:(NSEvent*)event {
-//   if (needToStartADrag(event))
-//     [dragController_ mouseDown:event];
-// }
-//
-// - (void)mouseDragged:(NSEvent*)event {
-//   [dragController_ mouseDragged:event];
-// }
-//
-// - (void)mouseUp:(NSEvent*)event {
-//   [dragController_ mouseUp:event];
-// }
-//
-// That's it. When user starts a drag, the client's callbacks will be invoked.
-
-@interface MouseDragController : NSObject {
- @private
-   NSPoint initialMouseLocation_;  // In NSWindow's coordinate system.
-   PanelDragState dragState_;
-   NSView<MouseDragControllerClient>* client_;  // Weak, owns this object.
-};
-
-- (MouseDragController*)
-    initWithClient:(NSView<MouseDragControllerClient>*)client;
-
-// Accessors.
-- (NSView<MouseDragControllerClient>*)client;
-- (NSPoint)initialMouseLocation;
-
-// These should be called from corresponding methods of hosting NSView.
-- (void)mouseDown:(NSEvent*)event;
-- (void)mouseDragged:(NSEvent*)event;
-- (void)mouseUp:(NSEvent*)event;
-@end
-
-#endif  // CHROME_BROWSER_UI_COCOA_PANELS_MOUSE_DRAG_CONTROLLER_H_