Add Vector2d classes that represent offsets, instead of using Point.

ui/aura/test/event_generator.cc

 // 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.
 
 #include "ui/aura/test/event_generator.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/events/event.h"
+#include "ui/gfx/vector2d_conversions.h"
 
 #if defined(USE_X11)
 #include <X11/Xlib.h>
 #include "ui/base/x/x11_util.h"
 #endif
 
 #if defined(OS_WIN)
 #include "ui/base/keycodes/keyboard_code_conversion.h"
 #endif
 
@@ skipping 99 matching lines @@
                            current_location_, flags_);
     Dispatch(mouseev);
     flags_ ^= ui::EF_RIGHT_MOUSE_BUTTON;
   }
 }
 
 void EventGenerator::MoveMouseTo(const gfx::Point& point, int count) {
   DCHECK_GT(count, 0);
   const ui::EventType event_type = (flags_ & ui::EF_LEFT_MOUSE_BUTTON) ?
       ui::ET_MOUSE_DRAGGED : ui::ET_MOUSE_MOVED;
-  const gfx::Point diff = point.Subtract(current_location_);
+  gfx::Vector2dF diff = point - current_location_;
   for (int i = 1; i <= count; i++) {
-    const gfx::Point move_point = current_location_.Add(
-        gfx::Point(diff.x() / count * i, diff.y() / count * i));
+    gfx::Vector2dF step = diff;
+    step.Scale(static_cast<float>(i) / count);
+    gfx::Point move_point = current_location_ + gfx::ToFlooredVector2d(step);

[Peter Kasting, 2012/10/31 01:04:41]

How come you ignored three points of my proposed code?:

(1) Make |i| float to remove static_cast
(2) Constructor-style init for non-POD types (Vector2dF)
(3) Use ToRoundedVector2d() to reduce error in individual moves

[danakj, 2012/10/31 16:55:46]

Oh, I didn't see that, assumed your lack of static cast was pseudocode.
Ah, okay.
I saw that, but didn't want to introduce behaviour changes in this CL. If you're
certain about this, then okay.

[Peter Kasting, 2012/10/31 17:13:41]

We're already introducing a behavior change because the old code did integer
division.  Given that lets's go all the way :)

     ui::MouseEvent mouseev(event_type, move_point, move_point, flags_);
     Dispatch(mouseev);
   }
   current_location_ = point;
 }
 
 void EventGenerator::MoveMouseRelativeTo(const Window* window,
                                          const gfx::Point& point) {
   gfx::Point root_point(point);
   Window::ConvertPointToTarget(window, root_window_, &root_point);
@@ skipping 192 matching lines @@
   TestKeyEvent keyev(native_event.get(), flags, false);
 #else
   ui::KeyEvent keyev(type, key_code, flags, false);
 #endif  // USE_X11
 #endif  // OS_WIN
   Dispatch(keyev);
 }
 
 }  // namespace test
 }  // namespace aura