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

chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc

Index: chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
diff --git a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
index a785d9d3d505a8b8fd10305b0d277614afc7afc3..8e8c1b85bcf361ec4366de06aa527bc97ac61c54 100644
--- a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
+++ b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
@@ -93,15 +93,15 @@ const int kCloseButtonHorzFuzz = 4;
 // Gets the bounds of |widget| relative to |parent|.
 gfx::Rect GetWidgetBoundsRelativeToParent(GtkWidget* parent,
                                           GtkWidget* widget) {
-  gfx::Point parent_pos = ui::GetWidgetScreenPosition(parent);
-  gfx::Point widget_pos = ui::GetWidgetScreenPosition(widget);
+  gfx::Vector2d parent_offset = ui::GetWidgetScreenOffset(parent);
+  gfx::Vector2d widget_offset = ui::GetWidgetScreenOffset(widget);
+  gfx::Vector2d offset_from_parent = widget_offset - parent_offset;
 
   GtkAllocation allocation;
   gtk_widget_get_allocation(widget, &allocation);
 
-  return gfx::Rect(widget_pos.x() - parent_pos.x(),
-                   widget_pos.y() - parent_pos.y(),
-                   allocation.width, allocation.height);
+  return gfx::Rect(gfx::PointAtOffsetFromOrigin(offset_from_parent),
+                   gfx::Size(allocation.width, allocation.height));

[Peter Kasting, 2012/10/29 23:06:33]

Nit: Assuming your earlier use of GetWidgetScreenBounds works correctly, seems
like this could use a similar trick to be condensed to something like:

  gfx::Rect bounds(ui::GetWidgetScreenBounds(widget));
  bounds.Offset(-ui::GetWidgetScreenOffset(parent));
  return bounds;

(Collapses to one line once we have Rect:operator+())

[danakj, 2012/10/29 23:21:41]

Done.

 }
 
 }  // namespace