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

Previously Point served two purposes, to be a position in 2d space, and also
an offset from the origin. This introduces a Vector2d class to represent an
offset, allowing typesafety checks for geometric operations.

The following are now the case:

Point +/- Vector = Point
- A point plus/minus an offset gives you a point at a position offset by the
vector.

Vector +/- Vector = Vector
- Two offsets can be added together to make a new offset.

Point - Point = Vector
- Subtracting one point from another gives you the offset between the two
points.

We add some new methods to perform these operations:

Rect::OffsetFromOrigin() gives the offset between the position of the rect
and the origin.

Point::OffsetFromOrigin() gives the offset between the point and the origin.

PointAtOffsetFromOrigin(Vector2d) converts a Vector2d to a Point at the given
offset away from the origin.

Rect::Offset(), Point::Add(), and Point::Subtract() now receive a Vector2d
instead of a point.

BUG=147395
R=sky

Review URL: https://codereview.chromium.org/11269022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@165198 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 3 deletions

diff --git a/ash/tooltips/tooltip_controller.cc b/ash/tooltips/tooltip_controller.cc
index 45c4785..0449645 100644
--- a/ash/tooltips/tooltip_controller.cc
+++ b/ash/tooltips/tooltip_controller.cc
@@ -450,9 +450,8 @@ void TooltipController::UpdateIfRequired() {
       GetTooltip()->Hide();
     } else {
       string16 tooltip_text(tooltip_text_);
-      gfx::Point widget_loc = curr_mouse_loc_;
-      widget_loc = widget_loc.Add(
-          tooltip_window_->GetBoundsInScreen().origin());
+      gfx::Point widget_loc = curr_mouse_loc_.Add(
+          tooltip_window_->GetBoundsInScreen().OffsetFromOrigin());
       GetTooltip()->SetText(tooltip_text, widget_loc);
       GetTooltip()->Show();
       tooltip_shown_timer_.Start(FROM_HERE,