Add early-injection capability to user scripts. I haven't yet

chrome/common/extensions/user_script.h

 // Copyright 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_EXTENSIONS_USER_SCRIPT_H_
 #define CHROME_COMMON_EXTENSIONS_USER_SCRIPT_H_
 
 #include <vector>
 #include <string>
 
 #include "base/file_path.h"
 #include "base/pickle.h"
 #include "chrome/common/extensions/url_pattern.h"
 #include "googleurl/src/gurl.h"
 
 // Represents a user script, either a standalone one, or one that is part of an
 // extension.
 class UserScript {
  public:
-  UserScript(){}
+  // Locations that user scripts can be run inside the document.
+  enum RunLocation {
+    DOCUMENT_START,  // After the documentElemnet is created, but before
+                     // anything else happens.
+    DOCUMENT_END,  // After the entire document is parsed. Same as
+                   // DOMContentLoaded.
+
+    RUN_LOCATION_LAST  // Leave this as the last item.
+  };
+
+  // Constructor. Default the run location to document end, which is like
+  // Greasemonkey and probably more useful for typical scripts.
+  UserScript() : run_location_(DOCUMENT_END) {}
 
   // The URL to retrieve the content of this script at.
   const GURL& url() const { return url_; }
   void set_url(const GURL& url) { url_ = url; }
 
   // The path to find the script at.
   const FilePath& path() const { return path_; }
   void set_path(const FilePath& path) { path_ = path; }
 
+  // The place in the document to run the script.
+  RunLocation run_location() const { return run_location_; }
+  void set_run_location(RunLocation location) { run_location_ = location; }
+
   // The globs, if any, that determine which pages this script runs against.
   // These are only used with "standalone" Greasemonkey-like user scripts.
   const std::vector<std::string>& globs() const { return globs_; }
   void add_glob(const std::string& glob) { globs_.push_back(glob); }
   void clear_globs() { globs_.clear(); }
 
   // The URLPatterns, if any, that determine which pages this script runs
   // against.
   const std::vector<URLPattern>& url_patterns() const { return url_patterns_; }
   void add_url_pattern(const URLPattern& pattern) {
@@ skipping 13 matching lines @@
   // correctly.
   void Unpickle(const ::Pickle& pickle, void** iter);
 
  private:
   // The URL to the content of the script.
   GURL url_;
 
   // The path to the content of the script.
   FilePath path_;
 
+  // The location to run the script inside the document.
+  RunLocation run_location_;
+
   // Greasemonkey-style globs that determine pages to inject the script into.
   // These are only used with standalone scripts.
   std::vector<std::string> globs_;
 
   // URLPatterns that determine pages to inject the script into. These are
   // only used with scripts that are part of extensions.
   std::vector<URLPattern> url_patterns_;
 };
 
 typedef std::vector<UserScript> UserScriptList;
 
 #endif  // CHROME_COMMON_EXTENSIONS_USER_SCRIPT_H_