Remove dead extensions tracking code.

extensions/browser/api/web_request/web_request_api_helpers.h

Index: extensions/browser/api/web_request/web_request_api_helpers.h
diff --git a/extensions/browser/api/web_request/web_request_api_helpers.h b/extensions/browser/api/web_request/web_request_api_helpers.h
index 049a5bb71dc4d84e8dea88cb6d7f429f40f3993c..c66c28416e9b4a3711cf851517e3de4fb3a41c3e 100644
--- a/extensions/browser/api/web_request/web_request_api_helpers.h
+++ b/extensions/browser/api/web_request/web_request_api_helpers.h
@@ -329,17 +329,6 @@ bool MergeOnAuthRequiredResponses(
 // Triggers clearing each renderer's in-memory cache the next time it navigates.
 void ClearCacheOnNavigation();
 
-// Tells renderer processes that the web request or declarative web request
-// API has been used by the extension with the given |extension_id| in the
-// given |browser_context_id| to collect UMA statistics on Page Load Times.
-// Needs to be called on the UI thread.
-void NotifyWebRequestAPIUsed(void* browser_context_id,
-                             const std::string& extension_id);
-
-// Send updates to |host| with information about what webRequest-related
-// extensions are installed.
-void SendExtensionWebRequestStatusToHost(content::RenderProcessHost* host);
-
 // Converts the |name|, |value| pair of a http header to a HttpHeaders
 // dictionary.
 std::unique_ptr<base::DictionaryValue> CreateHeaderDictionary(