Enhance chrome.app.window API with icon property

ui/gfx/image/image_skia_operations.cc

Index: ui/gfx/image/image_skia_operations.cc
diff --git a/ui/gfx/image/image_skia_operations.cc b/ui/gfx/image/image_skia_operations.cc
index f523abf54ecec41f722fe4d94d95089be90570ee..b118c24243712c8a8b03bc02cad89fbaf3dd18c9 100644
--- a/ui/gfx/image/image_skia_operations.cc
+++ b/ui/gfx/image/image_skia_operations.cc
@@ -423,6 +423,28 @@ class RotatedSource : public ImageSkiaSource {
   DISALLOW_COPY_AND_ASSIGN(RotatedSource);
 };
 
+class ImageWithBadgeSource : public gfx::CanvasImageSource {
+ public:
+  ImageWithBadgeSource(const ImageSkia& first, const ImageSkia& second)
+      : gfx::CanvasImageSource(first.size(), false /* is opaque */),
+        first_(first),
+        second_(second) {}
+
+  ~ImageWithBadgeSource() override {}
+
+  // gfx::CanvasImageSource override.
+  void Draw(Canvas* canvas) override {
+    canvas->DrawImageInt(first_, 0, 0);
+    canvas->DrawImageInt(second_, (first_.width() - second_.width()),
+                         (first_.height() - second_.height()));
+  }
+
+ private:
+  const ImageSkia first_;
+  const ImageSkia second_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageWithBadgeSource);
+};
 
 }  // namespace
 
@@ -548,4 +570,13 @@ ImageSkia ImageSkiaOperations::CreateRotatedImage(
 
 }
 
+// static
+ImageSkia ImageSkiaOperations::CreateImageWithBadge(const ImageSkia& first,
+                                                    const ImageSkia& second) {
+  if (first.isNull() || second.isNull())
+    return ImageSkia();

[stevenjb, 2016/08/08 22:26:46]

It seems reasonable that if 'first' (the icon) is valid but second is not, we
should return 'first' instead of an empty image? Either way we should document
the behavior in the header.

[Andra Paraschiv, 2016/08/09 11:34:47]

Yes, we could do this way. Also, should we return the badge icon as a default
icon if the first icon is not valid? Added this logic in the new patch set.

[Reilly Grant (use Gerrit), 2016/08/09 19:08:45]

If the icon is not yet available we should use the default placeholder app icon
and badge it with the icon of the app that created the window.

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

Done.

+
+  return ImageSkia(new ImageWithBadgeSource(first, second), first.size());
+}
+
 }  // namespace gfx