athena: Add a minimal executable for just the UI.

athena/screen/background_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "athena/screen/background_controller.h"
 
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace athena {
 
 class BackgroundView : public views::View {
  public:
   BackgroundView() {}
   virtual ~BackgroundView() {}
 
   void SetImage(const gfx::ImageSkia& image) {
     image_ = image;
     SchedulePaint();
   }
 
   // views::View
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
-    canvas->DrawImageInt(image_,
-                         0,
-                         0,
-                         image_.width(),
-                         image_.height(),
-                         0,
-                         0,
-                         width(),
-                         height(),
-                         true);
+    if (!image_.isNull()) {

[oshima, 2014/05/27 18:32:14]

can you set the background using SetupBackgroundImage()? I'd like to minimize
the difference in execution path between environments.

[sadrul, 2014/05/29 03:03:56]

Done.

+      canvas->DrawImageInt(image_,
+                           0,
+                           0,
+                           image_.width(),
+                           image_.height(),
+                           0,
+                           0,
+                           width(),
+                           height(),
+                           true);
+    } else {
+      canvas->DrawColor(SK_ColorRED);
+    }
   }
 
  private:
   gfx::ImageSkia image_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundView);
 };
 
 BackgroundController::BackgroundController(aura::Window* container) {
   // TODO(oshima): Using widget to just draw an image is probably
@@ skipping 15 matching lines @@
   // background_widget is owned by the container and will be deleted
   // when the container is deleted.
 }
 
 void BackgroundController::SetImage(const gfx::ImageSkia& image) {
   // TODO(oshima): implement cross fede animation.
   background_view_->SetImage(image);
 }
 
 }  // namespace athena