Add a development flag for the new material design Settings UI.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 220bf60ecf2d0006e19e03949cd32a54cac33f0b..6986eeeea5fabe7323d3e6a3fc16beaf9c6160b1 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -451,6 +451,9 @@ const char kEnableIPv6[]                    = "enable-ipv6";
 // Enables experimentation with launching ephemeral apps via hyperlinks.
 const char kEnableLinkableEphemeralApps[]   = "enable-linkable-ephemeral-apps";
 
+// Enables the material design Settings feature.
+const char kEnableMaterialDesignSettings[]  = "enable-md-settings";
+
 // Runs the Native Client inside the renderer process and enables GPU plugin
 // (internally adds lEnableGpuPlugin to the command line).
 const char kEnableNaCl[]                    = "enable-nacl";