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

chrome/browser/ui/views/tabs/tab_drag_controller.cc

Index: chrome/browser/ui/views/tabs/tab_drag_controller.cc
diff --git a/chrome/browser/ui/views/tabs/tab_drag_controller.cc b/chrome/browser/ui/views/tabs/tab_drag_controller.cc
index 146fa9b458baf2a3ff0a1288f68e0ef816e2650f..c4af459fccdc54c529034c53cfa5eb8a8cd3ddbf 100644
--- a/chrome/browser/ui/views/tabs/tab_drag_controller.cc
+++ b/chrome/browser/ui/views/tabs/tab_drag_controller.cc
@@ -112,7 +112,7 @@ class DockView : public views::View {
     bool rtl_ui = base::i18n::IsRTL();
     if (rtl_ui) {
       // Flip canvas to draw the mirrored tab images for RTL UI.
-      canvas->Translate(gfx::Point(width(), 0));
+      canvas->Translate(gfx::Vector2d(width(), 0));
       canvas->Scale(-1, 1);
     }
     int x_of_active_tab = width() / 2 + kTabSpacing / 2;
@@ -504,8 +504,7 @@ void TabDragController::Drag(const gfx::Point& point_in_screen) {
     Attach(source_tabstrip_, gfx::Point());
     if (detach_into_browser_ && static_cast<int>(drag_data_.size()) ==
         GetModel(source_tabstrip_)->count()) {
-      gfx::Point dragged_view_point = GetWindowOffset(point_in_screen);
-      RunMoveLoop(dragged_view_point);
+      RunMoveLoop(GetWindowOffset(point_in_screen));
       return;
     }
   }
@@ -1305,8 +1304,7 @@ void TabDragController::DetachIntoNewBrowserAndRunMoveLoop(
     // All the tabs in a browser are being dragged but all the tabs weren't
     // initially being dragged. For this to happen the user would have to
     // start dragging a set of tabs, the other tabs close, then detach.
-    gfx::Point dragged_view_point = GetWindowOffset(point_in_screen);
-    RunMoveLoop(dragged_view_point);
+    RunMoveLoop(GetWindowOffset(point_in_screen));
     return;
   }
 
@@ -1320,7 +1318,7 @@ void TabDragController::DetachIntoNewBrowserAndRunMoveLoop(
   std::vector<gfx::Rect> drag_bounds =
       CalculateBoundsForDraggedTabs(attached_point.x());
 
-  gfx::Point drag_offset;
+  gfx::Vector2d drag_offset;
   Browser* browser = CreateBrowserForDrag(
       attached_tabstrip_, point_in_screen, &drag_offset, &drag_bounds);
   Detach(DONT_RELEASE_CAPTURE);
@@ -1343,7 +1341,7 @@ void TabDragController::DetachIntoNewBrowserAndRunMoveLoop(
   RunMoveLoop(drag_offset);
 }
 
-void TabDragController::RunMoveLoop(const gfx::Point& drag_offset) {
+void TabDragController::RunMoveLoop(const gfx::Vector2d& drag_offset) {
   // If the user drags the whole window we'll assume they are going to attach to
   // another window and therefor want to reorder.
   move_behavior_ = REORDER;
@@ -1979,7 +1977,7 @@ bool TabDragController::AreTabsConsecutive() {
 Browser* TabDragController::CreateBrowserForDrag(
     TabStrip* source,
     const gfx::Point& point_in_screen,
-    gfx::Point* drag_offset,
+    gfx::Vector2d* drag_offset,
     std::vector<gfx::Rect>* drag_bounds) {
   gfx::Point center(0, source->height() / 2);
   views::View::ConvertPointToWidget(source, &center);
@@ -2006,7 +2004,7 @@ Browser* TabDragController::CreateBrowserForDrag(
       break; // Nothing to do for DETACH_ABOVE_OR_BELOW.
   }
 
-  *drag_offset = point_in_screen.Subtract(new_bounds.origin());
+  *drag_offset = point_in_screen - new_bounds.origin();
 
   Browser::CreateParams create_params(
       Browser::TYPE_TABBED,
@@ -2040,13 +2038,13 @@ gfx::Point TabDragController::GetCursorScreenPoint() {
   return screen_->GetCursorScreenPoint();
 }
 
-gfx::Point TabDragController::GetWindowOffset(
+gfx::Vector2d TabDragController::GetWindowOffset(
     const gfx::Point& point_in_screen) {
   TabStrip* owning_tabstrip = (attached_tabstrip_ && detach_into_browser_) ?
       attached_tabstrip_ : source_tabstrip_;
   views::View* toplevel_view = owning_tabstrip->GetWidget()->GetContentsView();
 
-  gfx::Point offset = point_in_screen;
-  views::View::ConvertPointFromScreen(toplevel_view, &offset);
-  return offset;
+  gfx::Point point = point_in_screen;
+  views::View::ConvertPointFromScreen(toplevel_view, &point);
+  return point.OffsetFromOrigin();
 }