Bringing back fast user switching on desktop user menu

chrome/browser/profiles/profile_avatar_icon_util.h

Index: chrome/browser/profiles/profile_avatar_icon_util.h
diff --git a/chrome/browser/profiles/profile_avatar_icon_util.h b/chrome/browser/profiles/profile_avatar_icon_util.h
index c7a4ff29bc3aebb862a0111e3d5ccca3030519ea..1a63ae8069ea44fe1487c0eea76980fb3f860135 100644
--- a/chrome/browser/profiles/profile_avatar_icon_util.h
+++ b/chrome/browser/profiles/profile_avatar_icon_util.h
@@ -39,12 +39,20 @@ extern const SkColor kAvatarBubbleAccountsBackgroundColor;
 extern const SkColor kAvatarBubbleGaiaBackgroundColor;
 extern const SkColor kUserManagerBackgroundColor;
 
+// Avatar shape.
+enum AvatarShape {
+  SHAPE_CIRCLE,  // Only available for desktop platforms
+  SHAPE_SQUARE,
+};
+
 // Returns a version of |image| of a specific size. Note that no checks are
 // done on the width/height so make sure they're reasonable values; in the
 // range of 16-256 is probably best.
 gfx::Image GetSizedAvatarIcon(const gfx::Image& image,
                               bool is_rectangle,
-                              int width, int height);
+                              int width,
+                              int height,
+                              AvatarShape shape=SHAPE_SQUARE);

[anthonyvd, 2016/06/28 14:50:46]

nit: I think you want spaces around = here

We also tend to avoid default arguments in favor of overloading where possible
(https://google.github.io/styleguide/cppguide.html#Default_Arguments). You could
instead overload the constructor and use delegating constructors.

For example: 

gfx:Image GetSizedAvatarIcon(..., AvatarShape shape) { ... }
gfx:Image GetSizedAvatarIcon(...) : GetSizedAvatarIcon(..., shape) { }

[Jane, 2016/06/28 16:32:53]

Thanks! Good to learn. I modified both functions to follow this format.
Regarding the space, git cl format does force that, but Roger told me to remove
them in a previous comment...

 
 // Returns a version of |image| suitable for use in menus.
 gfx::Image GetAvatarIconForMenu(const gfx::Image& image,