Clean up a few more unused globals.

content/public/test/test_launcher.cc

Index: content/public/test/test_launcher.cc
diff --git a/content/public/test/test_launcher.cc b/content/public/test/test_launcher.cc
index 0478645826f16bf1a4c95006c3316540886ac077..5964d55f9a349994c92569c4fa0a6f92b1d2e331 100644
--- a/content/public/test/test_launcher.cc
+++ b/content/public/test/test_launcher.cc
@@ -323,10 +323,6 @@ bool GetSwitchValueAsInt(const std::string& switch_name, int* result) {
 
 }  // namespace
 
-// The following is kept for historical reasons (so people that are used to
-// using it don't get surprised).
-const char kChildProcessFlag[]   = "child";
-
 const char kHelpFlag[]   = "help";
 
 const char kLaunchAsBrowser[] = "as-browser";