Remove CHECK around duplicate FLAG lookup.

webrtc/base/flags.cc

Index: webrtc/base/flags.cc
diff --git a/webrtc/base/flags.cc b/webrtc/base/flags.cc
index 0c0f4491c83057d8062d4d9f1e6ce3756c192ccb..1e42a427091a159606f159ea0aa2646459edfccf 100644
--- a/webrtc/base/flags.cc
+++ b/webrtc/base/flags.cc
@@ -257,8 +257,6 @@ int FlagList::SetFlagsFromCommandLine(int* argc, const char** argv,
 
 void FlagList::Register(Flag* flag) {
   assert(flag != NULL && strlen(flag->name()) > 0);
-  RTC_CHECK(!Lookup(flag->name())) << "flag " << flag->name()
-                                   << " declared twice";

[pthatcher1, 2016/06/30 20:49:39]

Then can we at least leave a comment here, perhaps something like this?

Warning: Don't call Lookup within Register because it accesses list_->name()
which may not be initialized yet.  

   flag->next_ = list_;
   list_ = flag;
 }