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

ash/wm/workspace/workspace_event_handler_unittest.cc

Index: ash/wm/workspace/workspace_event_handler_unittest.cc
diff --git a/ash/wm/workspace/workspace_event_handler_unittest.cc b/ash/wm/workspace/workspace_event_handler_unittest.cc
index 102268ae2c3db4fd317bf3716c430529a77f4f17..d67a123fd825d82caa45abe895e2fa733c6f2bf8 100644
--- a/ash/wm/workspace/workspace_event_handler_unittest.cc
+++ b/ash/wm/workspace/workspace_event_handler_unittest.cc
@@ -154,10 +154,12 @@ TEST_F(WorkspaceEventHandlerTest, DeleteWhenDragging) {
   aura::test::EventGenerator generator(window->GetRootWindow());
   generator.MoveMouseToCenterOf(window.get());
   generator.PressLeftButton();
-  generator.MoveMouseTo(generator.current_location().Add(gfx::Point(50, 50)));
+  generator.MoveMouseTo(
+      generator.current_location().Add(gfx::Vector2d(50, 50)));
   DCHECK_NE(bounds.origin().ToString(), window->bounds().origin().ToString());
   window.reset();
-  generator.MoveMouseTo(generator.current_location().Add(gfx::Point(50, 50)));
+  generator.MoveMouseTo(
+      generator.current_location().Add(gfx::Vector2d(50, 50)));
 }
 
 // Verifies deleting the window while in a run loop doesn't crash.
@@ -170,7 +172,7 @@ TEST_F(WorkspaceEventHandlerTest, DeleteWhileInRunLoop) {
   ASSERT_TRUE(aura::client::GetWindowMoveClient(window->parent()));
   MessageLoop::current()->DeleteSoon(FROM_HERE, window.get());
   aura::client::GetWindowMoveClient(window->parent())->RunMoveLoop(
-      window.release(), gfx::Point());
+      window.release(), gfx::Vector2d());
 }
 
 }  // namespace internal