Makes the launcher auto-hide for maximized windows. This turned out to

ash/launcher/launcher.h

Index: ash/launcher/launcher.h
diff --git a/ash/launcher/launcher.h b/ash/launcher/launcher.h
index 6825771cc4e31c2689e399b13d07cf092320d3b7..f419f8c7da9ab73fedda78910fed27318f8a2180 100644
--- a/ash/launcher/launcher.h
+++ b/ash/launcher/launcher.h
@@ -9,6 +9,8 @@
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ash/ash_export.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/base/animation/slide_animation.h"
 
 namespace aura {
 class Window;
@@ -32,14 +34,24 @@ class LauncherView;
 class LauncherDelegate;
 class LauncherModel;
 
-class ASH_EXPORT Launcher {
+class ASH_EXPORT Launcher : public ui::AnimationDelegate {
  public:
+  // How the background can be changed.
+  enum BackgroundChangeSpeed {
+    CHANGE_ANIMATE,
+    CHANGE_IMMEDIATE
+  };
+
   explicit Launcher(aura::Window* window_container);
   ~Launcher();
 
   // Sets the focus cycler.
   void SetFocusCycler(const internal::FocusCycler* focus_cycler);
 
+  // Sets whether the launcher renders a background. Default is false, but is
+  // set to true if a window overlaps the shelf.
+  void SetRendersBackground(bool value, BackgroundChangeSpeed speed);
+
   // Sets the width of the status area.
   void SetStatusWidth(int width);
   int GetStatusWidth();
@@ -57,6 +69,9 @@ class ASH_EXPORT Launcher {
 
   aura::Window* window_container() { return window_container_; }
 
+  // ui::AnimationDelegate overrides:
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+
  private:
   class DelegateView;
 
@@ -75,6 +90,15 @@ class ASH_EXPORT Launcher {
 
   scoped_ptr<LauncherDelegate> delegate_;
 
+  // Used to animate the background.
+  ui::SlideAnimation background_animation_;
+
+  // Whether we render a background.
+  bool renders_background_;
+
+  // Current alpha value of the background.
+  int background_alpha_;
+
   DISALLOW_COPY_AND_ASSIGN(Launcher);
 };