respect --force-compositing-mode for chrome: pages

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 47a201aa19ea5e887227d0d37fabb4637de116c4..44d595d3671fe326cf5975247d46793919885d79 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -37,6 +37,9 @@ const char kAllowScriptingGallery[]         = "allow-scripting-gallery";
 // websocket proxy.
 const char kAllowWebSocketProxy[]           = "allow-websocket-proxy";
 
+// Allow compositing on chrome:// pages.
+const char kAllowWebUICompositing[]         = "allow-webui-compositing";
+
 // Allows WebUI based OOBE. Note, WebUI will be used iff kWebUILogin is also
 // true.
 const char kAllowWebUIOobe[]                = "allow-webui-oobe";