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

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index 961010dc78651c0c71c39116adc4c3c6a9f4edfd..d7b8a51a6ff8382f256d5fc4a9f54f9dc6e98a6c 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -637,7 +637,7 @@ RenderWidgetHostViewWin::GetNativeViewAccessible() {
 }
 
 void RenderWidgetHostViewWin::MovePluginWindows(
-    const gfx::Point& scroll_offset,
+    const gfx::Vector2d& scroll_offset,
     const std::vector<webkit::npapi::WebPluginGeometry>& plugin_window_moves) {
   MovePluginWindowsHelper(m_hWnd, plugin_window_moves);
 }
@@ -1428,7 +1428,7 @@ void RenderWidgetHostViewWin::DrawBackground(const RECT& dirty_rect,
   if (!background_.empty()) {
     gfx::Rect dirty_area(dirty_rect);
     gfx::Canvas canvas(dirty_area.size(), ui::SCALE_FACTOR_100P, true);
-    canvas.Translate(gfx::Point().Subtract(dirty_area.origin()));
+    canvas.Translate(-dirty_area.DistanceFromOrigin());
 
     gfx::Rect dc_rect(dc->m_ps.rcPaint);
     // TODO(pkotwicz): Fix |background_| such that it is an ImageSkia.