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

chrome/renderer/user_script_slave.cc

 // Copyright (c) 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.
 
 #include "chrome/renderer/user_script_slave.h"
 
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/shared_memory.h"
 #include "chrome/common/resource_bundle.h"
@@ skipping 69 matching lines @@
     int body_length = 0;
     CHECK(pickle.ReadData(&iter, &body, &body_length));
 
     scripts_.push_back(script);
     script_contents_[script] = StringPiece(body, body_length);
   }
 
   return true;
 }
 
-bool UserScriptSlave::InjectScripts(WebFrame* frame) {
+bool UserScriptSlave::InjectScripts(WebFrame* frame,
+                                    UserScript::RunLocation location) {
   for (std::vector<UserScript*>::iterator script = scripts_.begin();
        script != scripts_.end(); ++script) {
-    if ((*script)->MatchesUrl(frame->GetURL())) {
+    if ((*script)->MatchesUrl(frame->GetURL()) &&
+        (*script)->run_location() == location) {
       std::string inject(kUserScriptHead);
       inject.append(api_js_.as_string());
       inject.append(script_contents_[*script].as_string());
       inject.append(kUserScriptTail);
       frame->ExecuteJavaScript(inject,
                                GURL((*script)->url().spec()),
                                -user_script_start_line_);
     }
   }
 
   return true;
 }