Use animated vector icon for app menu notification animation.

ui/gfx/paint_vector_icon.h

Index: ui/gfx/paint_vector_icon.h
diff --git a/ui/gfx/paint_vector_icon.h b/ui/gfx/paint_vector_icon.h
index 22000438accdd24e950f6b818e9adaf45c715438..76dc444ce60cb1a84f541a87b6052338cf60a6cf 100644
--- a/ui/gfx/paint_vector_icon.h
+++ b/ui/gfx/paint_vector_icon.h
@@ -15,6 +15,28 @@ namespace gfx {
 class Canvas;
 struct VectorIcon;
 
+// Describes an instance of an icon: an icon definition and a set of drawing
+// parameters.
+struct GFX_EXPORT IconDescription {
+  IconDescription(const IconDescription& other);
+
+  IconDescription(const VectorIcon& icon,
+                  int dip_size,
+                  SkColor color,
+                  const base::TimeDelta& elapsed_time,
+                  const VectorIcon& badge_icon);
+
+  ~IconDescription();
+
+  bool operator<(const IconDescription& other) const;

[sadrul, 2017/05/23 18:01:14]

I don't think < operator makes sense for IconDescription.

[Evan Stade, 2017/05/23 23:38:42]

Why not? This is just used as an ordering operation so we can use it as a key in
a map.

[sadrul, 2017/05/24 17:35:14]

I don't know what the result of comparing two non-animated IconDescription of
the same size + dip + color would mean.

Can you use a std::unordered_map() with a hash-function instead?

[Evan Stade, 2017/05/24 17:47:53]

Does it matter what the meaning of the comparison is? It just imposes a
deterministic ordering.
Aren't we supposed to avoid hash maps?

[sadrul, 2017/05/26 19:50:27]

Let's create a separate function for that, then, and not override < operator.
Can you link that explains why?

[Evan Stade, 2017/05/26 20:48:52]

I moved this to a separate struct, although I'd still like to understand why
that's important. We define operator< for the sake of std:: data structures a
lot, e.g. in gfx::Point, gfx::Rect, gfx::ColorSpace. When should we avoid it and
when is it ok?
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/rdxOHKzQmRY

+
+  const VectorIcon& icon;
+  int dip_size;
+  SkColor color;
+  const base::TimeDelta elapsed_time;
+  const VectorIcon& badge_icon;
+};
+
 GFX_EXPORT extern const VectorIcon kNoneIcon;
 
 // Draws a vector icon identified by |id| onto |canvas| at (0, 0). |color| is
@@ -36,6 +58,11 @@ GFX_EXPORT void PaintVectorIcon(
     SkColor color,
     const base::TimeDelta& elapsed_time = base::TimeDelta());
 
+// Creates an ImageSkia which will render the icon on demand.
+// TODO(estade): update clients to use this version and remove the other
+// CreateVectorIcon()s.
+GFX_EXPORT ImageSkia CreateVectorIcon(const IconDescription& params);
+
 // Creates an ImageSkia which will render the icon on demand. The size will come
 // from the .icon file (the 1x version, if multiple versions exist).
 GFX_EXPORT ImageSkia CreateVectorIcon(const VectorIcon& icon, SkColor color);