Fix folder icon animation in app list.

ui/gfx/transform_util.cc

Index: ui/gfx/transform_util.cc
diff --git a/ui/gfx/transform_util.cc b/ui/gfx/transform_util.cc
index 655ce57f2bb2b799cbf7da1b69164d97e5a42dd0..37d3e538196e6bdff10d5fb5ccd61679bf57980e 100644
--- a/ui/gfx/transform_util.cc
+++ b/ui/gfx/transform_util.cc
@@ -282,6 +282,15 @@ Transform GetScaleTransform(const Point& anchor, float scale) {
   return transform;
 }
 
+Transform GetRectTransform(const gfx::Rect& from, const gfx::Rect& to) {
+  Transform transform;
+  transform.Translate(to.x(), to.y());
+  transform.Scale(static_cast<double>(to.width()) / from.width(),

[Matt Giuca, 2014/11/04 01:05:17]

Going to have infinities if from.width() or from.height() is 0. I don't know
what will happen in that case but it's probably not an intended mode of
operation (and certainly won't get the intended result).

DCHECK_NE(0, from.width());
DCHECK_NE(0, from.height());

and document that from's width and height must be non-zero.

(Also think about what happens if width and height are negative; maybe just
DCHECK that too.)

[calamity, 2014/11/04 01:40:29]

Done.

+                  static_cast<double>(to.height()) / from.height());
+  transform.Translate(-from.x(), -from.y());
+  return transform;
+}
+
 DecomposedTransform::DecomposedTransform() {
   translate[0] = translate[1] = translate[2] = 0.0;
   scale[0] = scale[1] = scale[2] = 1.0;