Move DevTools out of ash and turn it to a component.

components/ui_devtools/switches.cc

Index: components/ui_devtools/switches.cc
diff --git a/components/ui_devtools/switches.cc b/components/ui_devtools/switches.cc
index c76f5b4ae2e96d1e0dd95118430426e500de14c2..b4762aa9720dd370ae42c69ee70141015b7ad602 100644
--- a/components/ui_devtools/switches.cc
+++ b/components/ui_devtools/switches.cc
@@ -4,12 +4,10 @@
 
 #include "components/ui_devtools/switches.h"
 
-namespace ui {
-namespace devtools {
+namespace ui_devtools {
 
 // Enables DevTools server for UI (mus, ash, etc). Value should be the port the
 // server is started on. Default port is 9332.
 const char kEnableUiDevTools[] = "enable-ui-devtools";
 
-}  // namespace devtools
-}  // namespace ui
+}  // namespace ui_devtools