Use icon for consistency with other touch bar APIs

atom/browser/ui/cocoa/atom_touch_bar.mm

@@ -601,7 +601,7 @@ static NSString* const ImageScrubberItemIdentifier = @"scrubber.image.item";
     NSScrubberImageItemView* view = [scrubber makeItemWithIdentifier:ImageScrubberItemIdentifier
                                                                owner:self];
     gfx::Image image;
-    if (item.Get("image", &image)) {
+    if (item.Get("icon", &image)) {
       view.image = image.AsNSImage();
     }
     itemView = view;

docs/api/structures/scrubber-item.md

@@ -1,4 +1,4 @@
 # ScrubberItem Object
 
 * `label` String - (Optional) The text to appear in this item
-* `image` NativeImage - (Optional) The image to appear in this item
+* `icon` NativeImage - (Optional) The image to appear in this item