For some vector icons, get the size from the vector definition.

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 73650a5a2cb63b33d3b9c0bf05874525afe7fa64..c95dc0bef07d0d943b212730d9f201eb24696551 100644
--- a/ui/gfx/paint_vector_icon.h
+++ b/ui/gfx/paint_vector_icon.h
@@ -35,6 +35,11 @@ GFX_EXPORT ImageSkia CreateVectorIconWithBadge(VectorIconId id,
                                                SkColor color,
                                                VectorIconId badge_id);
 
+// Creates a "primary UI" icon, i.e. one which is very often visible in the UI
+// and has been hand-tweaked to look good at a specific size at 1x and 2x scale
+// factors. The size is taken from the icon's canvas dimensions.
+GFX_EXPORT ImageSkia CreatePrimaryVectorIcon(VectorIconId id, SkColor color);
+
 #if defined(GFX_VECTOR_ICONS_UNSAFE) || defined(GFX_IMPLEMENTATION)
 // Takes a string of the format expected of .icon files and renders onto
 // a canvas. This should only be used as a debugging aid and should never be