Revert of Remove deprecated cursor event filter for Ozone

ash/display/mouse_cursor_event_filter_ozone.cc

Index: ash/display/mouse_cursor_event_filter_ozone.cc
diff --git a/ash/display/mouse_cursor_event_filter_ozone.cc b/ash/display/mouse_cursor_event_filter_ozone.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8c0487156bc2fbe677a3716de619d04900266737
--- /dev/null
+++ b/ash/display/mouse_cursor_event_filter_ozone.cc
@@ -0,0 +1,107 @@
+// 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.
+
+#include "ash/display/mouse_cursor_event_filter.h"
+
+#include "ash/shell.h"
+#include "ash/wm/coordinate_conversion.h"
+#include "ash/wm/window_util.h"
+#include "ui/wm/core/coordinate_conversion.h"
+
+namespace ash {
+
+void MouseCursorEventFilter::OnDisplayConfigurationChanged() {
+  src_edge_bounds_in_native_.SetRect(0, 0, 0, 0);
+  dst_edge_bounds_in_native_.SetRect(0, 0, 0, 0);
+}
+
+bool MouseCursorEventFilter::WarpMouseCursorIfNecessary(ui::MouseEvent* event) {
+  if (event->flags() & ui::EF_IS_SYNTHESIZED)
+    return false;
+
+  gfx::Point point_in_screen(event->location());
+  aura::Window* target = static_cast<aura::Window*>(event->target());
+  ::wm::ConvertPointToScreen(target, &point_in_screen);
+  return WarpMouseCursorInScreenCoords(target->GetRootWindow(),
+                                       point_in_screen);
+}
+
+bool MouseCursorEventFilter::WarpMouseCursorInScreenCoords(
+    aura::Window* target_root,
+    const gfx::Point& point_in_screen) {
+  if (Shell::GetScreen()->GetNumDisplays() <= 1 ||
+      mouse_warp_mode_ == WARP_NONE)
+    return false;
+
+  // Do not warp again right after the cursor was warped. Sometimes the offset
+  // is not long enough and the cursor moves at the edge of the destination
+  // display. See crbug.com/278885
+  // TODO(mukai): simplify the offset calculation below, it would not be
+  // necessary anymore with this flag.
+  if (was_mouse_warped_) {
+    was_mouse_warped_ = false;
+    return false;
+  }
+
+  aura::Window* root_at_point = wm::GetRootWindowAt(point_in_screen);
+  gfx::Point point_in_root = point_in_screen;
+  ::wm::ConvertPointFromScreen(root_at_point, &point_in_root);
+  gfx::Rect root_bounds = root_at_point->bounds();
+  int offset_x = 0;
+  int offset_y = 0;
+
+  // If the window is dragged between 2x display and 1x display,
+  // staring from 2x display, pointer location is rounded by the
+  // source scale factor (2x) so it will never reach the edge (which
+  // is odd). Shrink by scale factor of the display where the dragging
+  // started instead.  Only integral scale factor is supported for now.
+  int shrink = scale_when_drag_started_;
+  // Make the bounds inclusive to detect the edge.
+  root_bounds.Inset(0, 0, shrink, shrink);
+  gfx::Rect src_indicator_bounds = src_indicator_bounds_;
+  src_indicator_bounds.Inset(-shrink, -shrink, -shrink, -shrink);
+
+  if (point_in_root.x() <= root_bounds.x()) {
+    // Use -2, not -1, to avoid infinite loop of pointer warp.
+    offset_x = -2 * scale_when_drag_started_;
+  } else if (point_in_root.x() >= root_bounds.right()) {
+    offset_x = 2 * scale_when_drag_started_;
+  } else if (point_in_root.y() <= root_bounds.y()) {
+    offset_y = -2 * scale_when_drag_started_;
+  } else if (point_in_root.y() >= root_bounds.bottom()) {
+    offset_y = 2 * scale_when_drag_started_;
+  } else {
+    return false;
+  }
+
+  gfx::Point point_in_dst_screen(point_in_screen);
+  point_in_dst_screen.Offset(offset_x, offset_y);
+  aura::Window* dst_root = wm::GetRootWindowAt(point_in_dst_screen);
+
+  // Warp the mouse cursor only if the location is in the indicator bounds
+  // or the mouse pointer is in the destination root.
+  if (mouse_warp_mode_ == WARP_DRAG &&
+      dst_root != drag_source_root_ &&
+      !src_indicator_bounds.Contains(point_in_screen)) {
+    return false;
+  }
+
+  ::wm::ConvertPointFromScreen(dst_root, &point_in_dst_screen);
+
+  if (dst_root->bounds().Contains(point_in_dst_screen)) {
+    DCHECK_NE(dst_root, root_at_point);
+    was_mouse_warped_ = true;
+    dst_root->MoveCursorTo(point_in_dst_screen);
+    return true;
+  }
+  return false;
+}
+
+bool MouseCursorEventFilter::WarpMouseCursorIfNecessaryForTest(
+    aura::Window* target_root,
+    const gfx::Point& point_in_screen) {
+  return WarpMouseCursorInScreenCoords(target_root, point_in_screen);
+}
+
+}  // namespac