Fix flakiness of DesktopDragDropClientAuraX11Tests

ui/views/widget/desktop_aura/x11_move_loop.h

+// 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.
+
+#ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_H_
+#define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_H_
+
+#include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/x/x11_types.h"
+
+namespace views {
+
+// Runs a nested message loop and grabs the mouse. This is used to implement
+// dragging.
+class X11MoveLoop {
+ public:
+  virtual ~X11MoveLoop() {}
+
+  // Runs the nested message loop. While the mouse is grabbed, use |cursor| as
+  // the mouse cursor. Returns true if the move-loop is completed successfully.
+  // If the pointer-grab fails, or the move-loop is canceled by the user (e.g.
+  // by pressing escape), then returns false.
+  virtual bool RunMoveLoop(aura::Window* window, gfx::NativeCursor cursor) = 0;
+
+  // Updates the cursor while the move loop is running.
+  virtual void UpdateCursor(gfx::NativeCursor cursor) = 0;
+
+  // Ends the RunMoveLoop() that's currently in progress.
+  virtual void EndMoveLoop() = 0;
+
+  // Sets an image to be used during the drag.
+  virtual void SetDragImage(const gfx::ImageSkia& image,
+                            const gfx::Vector2dF& offset) = 0;
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_H_