Allow to have a transparent UA dependent background.

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 040608a887dd3f6613c507b6ff7fc62d7b77db00..60eec28cfb874866b61d6ead924402f304e67f0b 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1358,6 +1358,9 @@ bool NewTaskManagerEnabled() {
 }
 #endif  // defined(ENABLE_TASK_MANAGER)
 
+// Do not set a UA dependent background.
+const char kNoUADependentBackground[] = "no-ua-dependent-background";
+
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //