Aura: New window shadows, desktop background debug toggle

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 25b98b26ba8c4fb56d831296d9a0058be36bc55b..bc1e24ff276f7168babb5974088d6dc3efb3ec7d 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -28,6 +28,9 @@ namespace gfx {
 class Point;
 class Rect;
 }
+namespace ui {
+class Layer;
+}
 namespace views {
 class NonClientFrameView;
 class Widget;
@@ -78,6 +81,11 @@ class ASH_EXPORT Shell {
     MODE_OVERLAPPING,
   };
 
+  enum BackgroundMode {
+    BACKGROUND_IMAGE,
+    BACKGROUND_SOLID_COLOR
+  };
+
   enum Direction {
     FORWARD,
     BACKWARD
@@ -96,6 +104,10 @@ class ASH_EXPORT Shell {
     return compact_status_area_offset_;
   }
 
+  BackgroundMode desktop_background_mode() const {
+    return desktop_background_mode_;
+  }
+
   aura::Window* GetContainer(int container_id);
   const aura::Window* GetContainer(int container_id) const;
 
@@ -123,6 +135,9 @@ class ASH_EXPORT Shell {
   // Sets an appropriate window mode for the given screen resolution.
   void SetWindowModeForMonitorSize(const gfx::Size& monitor_size);
 
+  // Sets the desktop background mode.
+  void SetDesktopBackgroundMode(BackgroundMode mode);
+
   // Returns true if the screen is locked.
   bool IsScreenLocked() const;
 
@@ -261,6 +276,9 @@ class ASH_EXPORT Shell {
   // Can change at runtime.
   WindowMode window_mode_;
 
+  // Can change at runtime.
+  BackgroundMode desktop_background_mode_;
+
   // Owned by aura::RootWindow, cached here for type safety.
   internal::RootWindowLayoutManager* root_window_layout_;