Makes mojo WebUI run main only after page finishes loading

content/renderer/web_ui_mojo_context_state.cc

Index: content/renderer/web_ui_mojo_context_state.cc
diff --git a/content/renderer/web_ui_mojo_context_state.cc b/content/renderer/web_ui_mojo_context_state.cc
index 71ffe79ee4acb4475370ada3d87b31cdf19f87ea..18c61fae18c2a59ed46b764fc7dd20204673ba68 100644
--- a/content/renderer/web_ui_mojo_context_state.cc
+++ b/content/renderer/web_ui_mojo_context_state.cc
@@ -113,7 +113,7 @@ void WebUIMojoContextState::OnFetchModuleComplete(
   DCHECK_EQ(kModulePrefix,
       response.url().string().utf8().substr(0, arraysize(kModulePrefix) - 1));
   const std::string module =
-      response.url().string().utf8().substr(arraysize(kModulePrefix));
+      response.url().string().utf8().substr(arraysize(kModulePrefix) - 1);
   // We can't delete fetch right now as the arguments to this function come from
   // it and are used below. Instead use a scope_ptr to cleanup.
   scoped_ptr<ResourceFetcher> deleter(fetcher);