Add extensions code to use common updater in components/update_client/

extensions/browser/test_extensions_browser_client.cc

Index: extensions/browser/test_extensions_browser_client.cc
diff --git a/extensions/browser/test_extensions_browser_client.cc b/extensions/browser/test_extensions_browser_client.cc
index d98f7af31d540f732dd2fe4c8ce0b0a1d1bac8b4..da5ef277cc83d286fac614150ee925be4b7d0f9e 100644
--- a/extensions/browser/test_extensions_browser_client.cc
+++ b/extensions/browser/test_extensions_browser_client.cc
@@ -27,6 +27,11 @@ TestExtensionsBrowserClient::TestExtensionsBrowserClient(
 
 TestExtensionsBrowserClient::~TestExtensionsBrowserClient() {}
 
+void TestExtensionsBrowserClient::SetUpdateClientFactory(
+    const base::Callback<update_client::UpdateClient*(void)>& factory) {
+  update_client_factory_ = factory;
+}
+
 void TestExtensionsBrowserClient::SetIncognitoContext(BrowserContext* context) {
   // If a context is provided it must be off-the-record.
   DCHECK(!context || context->IsOffTheRecord());
@@ -204,4 +209,12 @@ TestExtensionsBrowserClient::GetExtensionWebContentsObserver(
   return nullptr;
 }
 
+scoped_refptr<update_client::UpdateClient>
+TestExtensionsBrowserClient::CreateUpdateClient(
+    content::BrowserContext* context) {
+  return update_client_factory_.is_null()
+             ? nullptr
+             : make_scoped_refptr(update_client_factory_.Run());
+}
+
 }  // namespace extensions