Tab dragging as implemented as a mus API.

services/ui/public/interfaces/window_tree.mojom

 // Copyright 2014 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.
 
 module ui.mojom;
 
 import "cc/ipc/surface_id.mojom";
 import "services/ui/public/interfaces/cursor.mojom";
 import "services/ui/public/interfaces/event_matcher.mojom";
 import "services/ui/public/interfaces/mus_constants.mojom";
@@ skipping 215 matching lines @@
   // See documentation for WindowTreeClient::OnWindowInputEvent().
   OnWindowInputEventAck(uint32 event_id, EventResult result);
 
   // See description of WindowManager for details.
   GetWindowManagerClient(associated WindowManagerClient& internal);
 
   // Returns a shared memory segment that contains two 16-bit ints packed into a
   // single Atomic32, which represent the current location of the mouse cursor
   // where the location is (x << 16) | y.
   GetCursorLocationMemory() => (handle<shared_buffer> cursor_buffer);
+
+  // Tells the window manager to start moving the window. OnChangeCompleted is
+  // called on whether the move was canceled. Because there's a delay between
+  // when a client sends this message and when the window manager starts acting
+  // on it, pass the cursor location at the start of the move.
+  PerformWindowMove(uint32 change_id, uint32 window_id, MoveLoopSource source,
+                    gfx.mojom.Point cursor);
+
+  // Tells the window manager to cancel any in progress window move started with
+  // StartWindowMove() and to revert the window bounds to how they were.
+  CancelWindowMove(uint32 window_id);
 };
 
 // Changes to windows are not sent to the connection that originated the
 // change. For example, if connection 1 changes the bounds of a window by
 // calling SetWindowBounds(), connection 1 does not receive
 // OnWindowBoundsChanged().
 interface WindowTreeClient {
   // Invoked when the client application has been embedded at |root|.
   // See Embed() on WindowTree for more details. |tree| will be a handle back to
   // the window manager service, unless the connection is to the root connection
@@ skipping 123 matching lines @@
   // See description of WindowManager for details.
   GetWindowManager(associated WindowManager& internal);
 };
 
 // Mus provides this interface as a way for clients to connect and obtain a
 // WindowTree handle with a supplied WindowTreeClient handle. The
 // WindowTreeClient has no roots, use NewTopLevelWindow() to create one.
 interface WindowTreeFactory {
   CreateWindowTree(WindowTree& tree_request, WindowTreeClient client);
 };