Refactors animation to allow for cleaner subclassing. I'm doing this

chrome/browser/gtk/download_item_gtk.cc

Index: chrome/browser/gtk/download_item_gtk.cc
diff --git a/chrome/browser/gtk/download_item_gtk.cc b/chrome/browser/gtk/download_item_gtk.cc
index fd17beb77430a55425c5ac0533d8f18d53911637..00f3ca1f7523b0501164560270daf01383a837c6 100644
--- a/chrome/browser/gtk/download_item_gtk.cc
+++ b/chrome/browser/gtk/download_item_gtk.cc
@@ -361,7 +361,7 @@ void DownloadItemGtk::OnDownloadUpdated(DownloadItem* download) {
 
       complete_animation_.reset(new SlideAnimation(this));
       complete_animation_->SetSlideDuration(kCompleteAnimationDurationMs);
-      complete_animation_->SetTweenType(SlideAnimation::NONE);
+      complete_animation_->SetTweenType(Tween::LINEAR);
       complete_animation_->Show();
       break;
     case DownloadItem::IN_PROGRESS:
@@ -801,7 +801,7 @@ gboolean DownloadItemGtk::OnProgressAreaExpose(GtkWidget* widget,
   // Create a transparent canvas.
   gfx::CanvasPaint canvas(event, false);
   if (download_item->complete_animation_.get()) {
-    if (download_item->complete_animation_->IsAnimating()) {
+    if (download_item->complete_animation_->is_animating()) {
       download_util::PaintDownloadComplete(&canvas,
           widget->allocation.x, widget->allocation.y,
           download_item->complete_animation_->GetCurrentValue(),
@@ -834,7 +834,7 @@ gboolean DownloadItemGtk::OnMenuButtonPressEvent(GtkWidget* button,
                                                  DownloadItemGtk* item) {
   // Stop any completion animation.
   if (item->complete_animation_.get() &&
-      item->complete_animation_->IsAnimating()) {
+      item->complete_animation_->is_animating()) {
     item->complete_animation_->End();
   }