Refactor code that defers extension background page loading

extensions/browser/test_extensions_browser_client.h

Index: extensions/browser/test_extensions_browser_client.h
diff --git a/extensions/browser/test_extensions_browser_client.h b/extensions/browser/test_extensions_browser_client.h
index b7932590ddfe64a1baef11f46317fa1ca3923706..5bcae6f88d46129f4528eaf507b933ae7e334c92 100644
--- a/extensions/browser/test_extensions_browser_client.h
+++ b/extensions/browser/test_extensions_browser_client.h
@@ -15,10 +15,17 @@ namespace extensions {
 // this class should call ExtensionsBrowserClient::Set() with its instance.
 class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
  public:
-  // |context| is required and must not be an incognito context.
+  // |main_context| is required and must not be an incognito context.
   explicit TestExtensionsBrowserClient(content::BrowserContext* main_context);
   virtual ~TestExtensionsBrowserClient();
 
+  void set_defer_loading_background_hosts(bool defer) {
+    defer_loading_background_hosts_ = defer;
+  }
+  void set_extension_system_factory(ExtensionSystemProvider* factory) {
+    extension_system_factory_ = factory;
+  }
+
   // Associates an incognito context with |main_context_|.
   void SetIncognitoContext(content::BrowserContext* incognito_context);
 
@@ -82,6 +89,12 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
   content::BrowserContext* main_context_;       // Not owned.
   content::BrowserContext* incognito_context_;  // Not owned, defaults to NULL.
 
+  // The return value for DeferLoadingBackgroundHosts().
+  bool defer_loading_background_hosts_;
+
+  // The return value for GetExtensionSystemFactory().
+  ExtensionSystemProvider* extension_system_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(TestExtensionsBrowserClient);
 };