Map ET_POINTER_MOVED to ET_MOUSE_DRAGGED when a mouse button is down.

ui/events/event_unittest.cc

Index: ui/events/event_unittest.cc
diff --git a/ui/events/event_unittest.cc b/ui/events/event_unittest.cc
index 3ffc0a78ec8cdc2c7d8d707a004beac9db1386e1..09e25fba6252ed4271f5a51e57147edf8e75f83d 100644
--- a/ui/events/event_unittest.cc
+++ b/ui/events/event_unittest.cc
@@ -898,7 +898,13 @@ TEST(EventTest, PointerEventToMouseEvent) {
       {ui::ET_POINTER_DOWN, ui::ET_MOUSE_PRESSED, gfx::Point(10, 20),
        gfx::Point(110, 120), 0},
       {ui::ET_POINTER_MOVED, ui::ET_MOUSE_MOVED, gfx::Point(20, 10),
+       gfx::Point(1, 2), 0},
+      {ui::ET_POINTER_MOVED, ui::ET_MOUSE_DRAGGED, gfx::Point(20, 10),
        gfx::Point(1, 2), EF_LEFT_MOUSE_BUTTON},
+      {ui::ET_POINTER_MOVED, ui::ET_MOUSE_DRAGGED, gfx::Point(20, 10),
+       gfx::Point(1, 2), EF_RIGHT_MOUSE_BUTTON},
+      {ui::ET_POINTER_MOVED, ui::ET_MOUSE_DRAGGED, gfx::Point(20, 10),
+       gfx::Point(1, 2), EF_MIDDLE_MOUSE_BUTTON},
       {ui::ET_POINTER_ENTERED, ui::ET_MOUSE_ENTERED, gfx::Point(), gfx::Point(),
        EF_MIDDLE_MOUSE_BUTTON | EF_RIGHT_MOUSE_BUTTON},
       {ui::ET_POINTER_EXITED, ui::ET_MOUSE_EXITED, gfx::Point(5, 1),