Enhance chrome.app.window API with icon property

ui/gfx/image/image_skia_operations.h

Index: ui/gfx/image/image_skia_operations.h
diff --git a/ui/gfx/image/image_skia_operations.h b/ui/gfx/image/image_skia_operations.h
index a22a8408d98e573368abcb91ba8bfde2c12d56eb..b366ab9b0f5806cc2ebc77d61ed0bc13664b2e1e 100644
--- a/ui/gfx/image/image_skia_operations.h
+++ b/ui/gfx/image/image_skia_operations.h
@@ -93,6 +93,13 @@ class GFX_EXPORT ImageSkiaOperations {
       const ImageSkia& source,
       SkBitmapOperations::RotationAmount rotation);
 
+  // Creates an icon by painting the second icon as a badge to the first one.
+  // The second icon is in the right corner of the first icon. If the icon
+  // is valid and the badge is not, the icon will be returned. Otherwise, if
+  // the badge is valid and the icon is not, the badge icon will be returned.

[stevenjb, 2016/08/09 16:59:32]

This seems overly complex. An empty |badge| seems reasonable, but if |icon| is
invalid we should just return an empty image.

[Andra Paraschiv, 2016/08/10 14:19:57]

Done.

+  static ImageSkia CreateIconWithBadge(const ImageSkia& icon,
+                                       const ImageSkia& badge);
+
  private:
   ImageSkiaOperations();  // Class for scoping only.
 };