Add error description to the DidFailProvisionalLoad callback.

content/renderer/mock_content_renderer_client.h

Index: content/renderer/mock_content_renderer_client.h
diff --git a/content/renderer/mock_content_renderer_client.h b/content/renderer/mock_content_renderer_client.h
index ea25c4f62ef547667f9b8db17400be0d7421a0ce..12789dbdab515b491e2a1dcedbf25abebaaf9c96 100644
--- a/content/renderer/mock_content_renderer_client.h
+++ b/content/renderer/mock_content_renderer_client.h
@@ -30,9 +30,11 @@ class MockContentRendererClient : public ContentRendererClient {
   virtual void ShowErrorPage(RenderView* render_view,
                              WebKit::WebFrame* frame,
                              int http_status_code) OVERRIDE;
-  virtual std::string GetNavigationErrorHtml(
+  virtual void GetNavigationErrorStrings(
       const WebKit::WebURLRequest& failed_request,
-      const WebKit::WebURLError& error) OVERRIDE;
+      const WebKit::WebURLError& error,
+      std::string* error_html,
+      string16* error_description) OVERRIDE;
   virtual bool RunIdleHandlerWhenWidgetsHidden() OVERRIDE;
   virtual bool AllowPopup(const GURL& creator) OVERRIDE;
   virtual bool ShouldFork(WebKit::WebFrame* frame,