Remove dead extensions tracking code.

extensions/browser/api/web_request/web_request_api.cc

Index: extensions/browser/api/web_request/web_request_api.cc
diff --git a/extensions/browser/api/web_request/web_request_api.cc b/extensions/browser/api/web_request/web_request_api.cc
index 829ebb512eb72d044537eb4afa30a5f800fcf704..36d82589a874b0c0f9ca910360f958efff65fb50 100644
--- a/extensions/browser/api/web_request/web_request_api.cc
+++ b/extensions/browser/api/web_request/web_request_api.cc
@@ -2148,12 +2148,6 @@ WebRequestInternalAddEventListenerFunction::Run() {
 
   helpers::ClearCacheOnNavigation();
 
-  if (!extension_id_safe().empty()) {
-    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
-                            base::Bind(&helpers::NotifyWebRequestAPIUsed,
-                                       profile_id(), extension_id_safe()));
-  }
-
   return RespondNow(NoArguments());
 }