Split extension_base.* out of bindings_utils.*.

BUG=
TEST=

Review URL: http://codereview.chromium.org/7767011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98743 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/renderer/extensions/renderer_extension_bindings.cc b/chrome/renderer/extensions/renderer_extension_bindings.cc
index 3990f61..b3a8ad9 100644
--- a/chrome/renderer/extensions/renderer_extension_bindings.cc
+++ b/chrome/renderer/extensions/renderer_extension_bindings.cc
@@ -14,14 +14,12 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/extensions/bindings_utils.h"
 #include "chrome/renderer/extensions/event_bindings.h"
+#include "chrome/renderer/extensions/extension_base.h"
 #include "chrome/renderer/extensions/extension_dispatcher.h"
 #include "content/renderer/render_thread.h"
 #include "content/renderer/render_view.h"
 #include "grit/renderer_resources.h"
 
-using bindings_utils::GetStringResource;
-using bindings_utils::ExtensionBase;
-
 // Message passing API example (in a content script):
 // var extension =
 //    new chrome.Extension('00123456789abcdef0123456789abcdef0123456');