Implement ResourceQueue, an object that makes it easy to delay starting

chrome/browser/renderer_host/resource_dispatcher_host.h

Index: chrome/browser/renderer_host/resource_dispatcher_host.h
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.h b/chrome/browser/renderer_host/resource_dispatcher_host.h
index a48cebe4667b0b1851ef49751141739c07103bcd..3dba76761fec295fd10f3f197fddfe0b6cd251d6 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.h
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.h
@@ -23,6 +23,7 @@
 #include "base/timer.h"
 #include "chrome/common/child_process_info.h"
 #include "chrome/browser/privacy_blacklist/blocked_response.h"
+#include "chrome/browser/renderer_host/resource_queue.h"
 #include "ipc/ipc_message.h"
 #include "net/url_request/url_request.h"
 #include "webkit/glue/resource_type.h"
@@ -41,6 +42,7 @@ class SSLClientAuthHandler;
 class UserScriptListener;
 class URLRequestContext;
 class WebKitThread;
+struct GlobalRequestID;
 struct ViewHostMsg_Resource_Request;
 struct ViewMsg_ClosePage_Params;
 
@@ -86,25 +88,6 @@ class ResourceDispatcherHost : public URLRequest::Delegate {
                                     const GURL& new_url) = 0;
   };
 
-  // Uniquely identifies a URLRequest.
-  struct GlobalRequestID {
-    GlobalRequestID() : child_id(-1), request_id(-1) {
-    }
-    GlobalRequestID(int child_id, int request_id)
-        : child_id(child_id),
-          request_id(request_id) {
-    }
-
-    int child_id;
-    int request_id;
-
-    bool operator<(const GlobalRequestID& other) const {
-      if (child_id == other.child_id)
-        return request_id < other.request_id;
-      return child_id < other.child_id;
-    }
-  };
-
   ResourceDispatcherHost();
   ~ResourceDispatcherHost();
 
@@ -249,7 +232,7 @@ class ResourceDispatcherHost : public URLRequest::Delegate {
   void RemoveObserver(Observer* obs);
 
   // Retrieves a URLRequest.  Must be called from the IO thread.
-  URLRequest* GetURLRequest(GlobalRequestID request_id) const;
+  URLRequest* GetURLRequest(const GlobalRequestID& request_id) const;
 
   // Notifies our observers that a request has been cancelled.
   void NotifyResponseCompleted(URLRequest* request, int process_unique_id);
@@ -414,6 +397,9 @@ class ResourceDispatcherHost : public URLRequest::Delegate {
   // is not empty.
   base::RepeatingTimer<ResourceDispatcherHost> update_load_states_timer_;
 
+  // Handles the resource requests from the moment we want to start them.
+  ResourceQueue resource_queue_;
+
   // We own the download file writing thread and manager
   scoped_refptr<DownloadFileManager> download_file_manager_;