Move Render(View|Widget)Host and associated classes to content namespace.

chrome/test/base/ui_test_utils.cc

Index: chrome/test/base/ui_test_utils.cc
diff --git a/chrome/test/base/ui_test_utils.cc b/chrome/test/base/ui_test_utils.cc
index 4ecb02616d9b02ec8f2c0f43720158b353a01776..e50d332b63e8e38705050fcf6513bffe01fed0c2 100644
--- a/chrome/test/base/ui_test_utils.cc
+++ b/chrome/test/base/ui_test_utils.cc
@@ -75,6 +75,8 @@ using content::DomOperationNotificationDetails;
 using content::NavigationController;
 using content::NavigationEntry;
 using content::OpenURLParams;
+using content::RenderViewHost;
+using content::RenderWidgetHost;
 using content::Referrer;
 using content::WebContents;