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

ash/wm/gestures/long_press_affordance_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/gestures/long_press_affordance_handler.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/shell.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell_window_ids.h"
@@ skipping 185 matching lines @@
   }
 
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
     gfx::Point center(GetPreferredSize().width() / 2,
                       GetPreferredSize().height() / 2);
     canvas->Save();
 
     gfx::Transform scale;
     scale.SetScale(current_scale_, current_scale_);
     // We want to scale from the center.
-    canvas->Translate(gfx::Point(center.x(), center.y()));
+    canvas->Translate(gfx::Vector2d(center.x(), center.y()));

[sky, 2012/10/26 21:37:50]

This too feels cumbersome. If we're saying a distance is represented by a Vector
shouldn't |center| be a vector?

[Peter Kasting, 2012/10/26 21:50:12]

Seems like this should be:

  canvas->Translate(center.DistanceFromOrigin());

[danakj, 2012/10/26 21:59:43]

Ya certainly, or just have

gfx::Vector2d centerOffset(width / 2, height / 2); and then pass that directly.

[Peter Kasting, 2012/10/26 22:04:06]

The reason I didn't do this is because |center| is also used below.  Of course,
perhaps those uses would also prefer vectors, I don't know.

     canvas->Transform(scale);
-    canvas->Translate(gfx::Point(-center.x(), -center.y()));
+    canvas->Translate(gfx::Vector2d(-center.x(), -center.y()));
 
     // Paint affordance glow
     int start_radius = kAffordanceInnerRadius - kAffordanceGlowWidth;
     int end_radius = kAffordanceOuterRadius + kAffordanceGlowWidth;
     const int num_colors = 3;
     SkScalar pos[num_colors] = {0, 0.5, 1};
     SkColor colors[num_colors] = {kAffordanceGlowEndColor,
         kAffordanceGlowStartColor, kAffordanceGlowEndColor};
     PaintAffordanceGlow(canvas, center, start_radius, end_radius, colors, pos,
         num_colors);
@@ skipping 150 matching lines @@
     default:
       view_.reset();
       tap_down_touch_id_ = -1;
       tap_down_display_id_ = 0;
       break;
   }
 }
 
 }  // namespace internal
 }  // namespace ash