Delay request loading until all user scripts that request depends on are ready.

chrome/browser/renderer_host/resource_dispatcher_host.cc

Index: chrome/browser/renderer_host/resource_dispatcher_host.cc
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.cc b/chrome/browser/renderer_host/resource_dispatcher_host.cc
index 0066ad67f8d7dbca7d2c907261b751fea2213feb..b205fd0ddfe8917690365cad0e37d3167f7f0f30 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.cc
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/download/download_request_manager.h"
 #include "chrome/browser/download/save_file_manager.h"
+#include "chrome/browser/extensions/user_script_listener.h"
 #include "chrome/browser/external_protocol_handler.h"
 #include "chrome/browser/in_process_webkit/webkit_thread.h"
 #include "chrome/browser/login_prompt.h"
@@ -252,6 +253,8 @@ ResourceDispatcherHost::ResourceDispatcherHost(MessageLoop* io_loop)
       download_request_manager_(new DownloadRequestManager(io_loop, ui_loop_)),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           save_file_manager_(new SaveFileManager(ui_loop_, io_loop, this))),
+      ALLOW_THIS_IN_INITIALIZER_LIST(user_script_listener_(
+          new UserScriptListener(ui_loop_, io_loop, this))),
       safe_browsing_(new SafeBrowsingService),
       webkit_thread_(new WebKitThread),
       request_id_(-1),
@@ -282,6 +285,8 @@ ResourceDispatcherHost::~ResourceDispatcherHost() {
        iter != ids.end(); ++iter) {
     CancelBlockedRequestsForRoute(iter->first, iter->second);
   }
+
+  user_script_listener_->OnResourceDispatcherHostGone();
 }
 
 void ResourceDispatcherHost::Initialize() {
@@ -1247,6 +1252,11 @@ void ResourceDispatcherHost::BeginRequestInternal(URLRequest* request) {
     // its content should be filtered) and start it itself.
     return;
   }
+  if (!user_script_listener_->ShouldStartRequest(request)) {
+    // This request depends on some user scripts that haven't loaded yet.  The
+    // UserScriptListener will resume the request when they're ready.
+    return;
+  }
   request->Start();
 
   // Make sure we have the load state monitor running