Renames SystemBackgroundController to ColoredWindowController and
makes it a bit more generic. I'm going to need it for some animations.

BUG=155179
TEST=none
Review URL: https://codereview.chromium.org/11086064

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@161349 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ash/root_window_controller.h b/ash/root_window_controller.h
index c88795d..f1a0926 100644
--- a/ash/root_window_controller.h
+++ b/ash/root_window_controller.h
@@ -25,9 +25,9 @@
 class ToplevelWindowEventHandler;
 namespace internal {
 
+class ColoredWindowController;
 class RootWindowLayoutManager;
 class ScreenDimmer;
-class SystemBackgroundController;
 class SystemModalContainerLayoutManager;
 class WorkspaceController;
 
@@ -98,7 +98,7 @@
   // this, portions of the root window that aren't covered by layers will be
   // painted white; this can show up if e.g. it takes a long time to decode the
   // desktop background image when displaying the login screen.
-  scoped_ptr<SystemBackgroundController> background_;
+  scoped_ptr<ColoredWindowController> background_;
 
   scoped_ptr<ScreenDimmer> screen_dimmer_;
   scoped_ptr<WorkspaceController> workspace_controller_;