Add the ability for keys to be drawn as an image.

services/keyboard_native/key_layout.h

Index: services/keyboard_native/key_layout.h
diff --git a/services/keyboard_native/key_layout.h b/services/keyboard_native/key_layout.h
index cf579e7c191116137de016937a0be5916858ce6a..293ce9785ef604301cb4f6c983f7e3344db7b3f2 100644
--- a/services/keyboard_native/key_layout.h
+++ b/services/keyboard_native/key_layout.h
@@ -12,7 +12,10 @@
 #include "base/memory/weak_ptr.h"
 #include "mojo/public/cpp/bindings/callback.h"
 #include "mojo/services/geometry/public/interfaces/geometry.mojom.h"
+#include "mojo/tools/embed/data.h"
 #include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkImageDecoder.h"
+#include "third_party/skia/include/core/SkStream.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 
@@ -77,6 +80,21 @@ class KeyLayout {
     DISALLOW_COPY_AND_ASSIGN(TextKey);
   };
 
+  // An implementation of Key that draws itself as an image.
+  class ImageKey : public TextKey {
+   public:
+    ImageKey(const char* text,
+             base::Callback<void(const TextKey&)> touch_up_callback,
+             const mojo::embed::Data& data);
+    ~ImageKey() override;
+    void Draw(SkCanvas* canvas, SkPaint paint, const gfx::RectF& rect) override;
+
+   private:
+    SkBitmap bitmap_;
+
+    DISALLOW_COPY_AND_ASSIGN(ImageKey);
+  };
+
   // initializes the *_layout_ vectors.
   void InitLayouts();