Add new user script injection point: document_idle.

chrome/browser/extensions/user_script_master.cc

Index: chrome/browser/extensions/user_script_master.cc
diff --git a/chrome/browser/extensions/user_script_master.cc b/chrome/browser/extensions/user_script_master.cc
index 024de802c38cd67ce980a428dabefa88477a1094..2da2d8f8952dfaa3738870116cee0804d21f37de 100644
--- a/chrome/browser/extensions/user_script_master.cc
+++ b/chrome/browser/extensions/user_script_master.cc
@@ -166,6 +166,11 @@ void UserScriptMaster::ScriptReloader::LoadScriptsFromDirectory(
          file = enumerator.Next()) {
       result->push_back(UserScript());
       UserScript& user_script = result->back();
+
+      // We default standalone user scripts to document-end for better
+      // Greasemonkey compatibility.
+      user_script.set_run_location(UserScript::DOCUMENT_END);
+
       // Push single js file in this UserScript.
       GURL url(std::string(chrome::kUserScriptScheme) + ":/" +
           net::FilePathToFileURL(file).ExtractFileName());