Move CommandLine to base namespace.

ash/desktop_background/desktop_background_controller.h

Index: ash/desktop_background/desktop_background_controller.h
diff --git a/ash/desktop_background/desktop_background_controller.h b/ash/desktop_background/desktop_background_controller.h
index 38c08c31c5b32af1abca439d693b2930670c399a..d7c1d06b263a481a85990835150136ebfc08de8a 100644
--- a/ash/desktop_background/desktop_background_controller.h
+++ b/ash/desktop_background/desktop_background_controller.h
@@ -19,12 +19,14 @@
 
 typedef unsigned int SkColor;
 
-class CommandLine;
-
 namespace aura {
 class Window;
 }
 
+namespace base {
+class CommandLine;
+}
+
 namespace ash {
 
 enum WallpaperLayout {
@@ -81,7 +83,7 @@ class ASH_EXPORT DesktopBackgroundController
     return desktop_background_mode_;
   }
 
-  void set_command_line_for_testing(CommandLine* command_line) {
+  void set_command_line_for_testing(base::CommandLine* command_line) {
     command_line_for_testing_ = command_line;
   }
 
@@ -189,7 +191,7 @@ class ASH_EXPORT DesktopBackgroundController
   static gfx::Size GetMaxDisplaySizeInNative();
 
   // If non-NULL, used in place of the real command line.
-  CommandLine* command_line_for_testing_;
+  base::CommandLine* command_line_for_testing_;
 
   // Can change at runtime.
   bool locked_;