Simplify BrowserContext by removing redundant methods.

extensions/shell/browser/shell_oauth2_token_service_delegate.cc

Index: extensions/shell/browser/shell_oauth2_token_service_delegate.cc
diff --git a/extensions/shell/browser/shell_oauth2_token_service_delegate.cc b/extensions/shell/browser/shell_oauth2_token_service_delegate.cc
index 89eb2120447028e417e22256bded7dcdc1020ad4..759f3e2f24c829ccdc40f6983fb1209d4b7f1d9a 100644
--- a/extensions/shell/browser/shell_oauth2_token_service_delegate.cc
+++ b/extensions/shell/browser/shell_oauth2_token_service_delegate.cc
@@ -6,6 +6,8 @@
 
 #include <vector>
 
+#include "content/public/browser/storage_partition.h"
+
 namespace extensions {
 
 ShellOAuth2TokenServiceDelegate::ShellOAuth2TokenServiceDelegate(
@@ -40,7 +42,8 @@ ShellOAuth2TokenServiceDelegate::CreateAccessTokenFetcher(
 
 net::URLRequestContextGetter*
 ShellOAuth2TokenServiceDelegate::GetRequestContext() const {
-  return browser_context_->GetRequestContext();
+  return content::BrowserContext::GetDefaultStoragePartition(browser_context_)->
+      GetURLRequestContext();
 }
 
 std::vector<std::string> ShellOAuth2TokenServiceDelegate::GetAccounts() {