content::ResourceDispatcherHostImpl changes for stale-while-revalidate

content/browser/loader/resource_dispatcher_host_impl.h

Index: content/browser/loader/resource_dispatcher_host_impl.h
diff --git a/content/browser/loader/resource_dispatcher_host_impl.h b/content/browser/loader/resource_dispatcher_host_impl.h
index 4951416730339897670b865961385f478e516c08..2def36031fa8cffe077c609bea46dd80c0cb2e8c 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.h
+++ b/content/browser/loader/resource_dispatcher_host_impl.h
@@ -25,6 +25,7 @@
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "content/browser/download/download_resource_handler.h"
+#include "content/browser/loader/async_revalidation_driver.h"
 #include "content/browser/loader/global_routing_id.h"
 #include "content/browser/loader/resource_loader.h"
 #include "content/browser/loader/resource_loader_delegate.h"
@@ -51,10 +52,12 @@ class FilePath;
 }
 
 namespace net {
+class URLRequestContext;
 class URLRequestJobFactory;
 }
 
 namespace storage {
+class BlobStorageContext;
 class ShareableFileReference;
 }
 
@@ -304,9 +307,28 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
     uint64 upload_size;
   };
 
+  // Request parameters that are not included in ResourceHostMsg_Request. Used
+  // as an argument to ConstructRequest();
+  struct ExtraRequestParams {
+    ExtraRequestParams();
+
+    storage::BlobStorageContext* blob_context;
+    int child_id;
+    bool is_sync_load;
+    bool use_embedded_identity;
+    bool support_async_revalidation;
+    const net::HttpRequestHeaders* extra_headers;
+  };
+
   // Map from ProcessID+RouteID pair to the "most interesting" LoadState.
   typedef std::map<GlobalRoutingID, LoadInfo> LoadInfoMap;
 
+  // Map from ResourceContext, HttpCache and url key to AsyncRevalidationDriver
+  // object.
+  typedef std::map<AsyncRevalidationKey,
+                   AsyncRevalidationDriver*,
+                   AsyncRevalidationKey::LessThan> AsyncRevalidationMap;
+
   // ResourceLoaderDelegate implementation:
   ResourceDispatcherHostLoginDelegate* CreateLoginDelegate(
       ResourceLoader* loader,
@@ -435,6 +457,11 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
                     IPC::Message* sync_result,  // only valid for sync
                     int route_id);  // only valid for async
 
+  scoped_ptr<net::URLRequest> ConstructRequest(
+      net::URLRequestContext* request_context,
+      const ResourceHostMsg_Request& request_data,
+      const ExtraRequestParams& extra_params);
+
   // Creates a ResourceHandler to be used by BeginRequest() for normal resource
   // loading.
   scoped_ptr<ResourceHandler> CreateResourceHandler(
@@ -507,6 +534,11 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
                                int child_id,
                                bool is_sync_load);
 
+  void BeginAsyncRevalidation(net::URLRequest* for_request);
+  void OnAsyncRevalidationComplete(const AsyncRevalidationKey& key);
+  void CancelAsyncRevalidationsForResourceContext(
+      ResourceContext* resource_context);
+
   LoaderMap pending_loaders_;
 
   // Collection of temp files downloaded for child processes via
@@ -585,6 +617,14 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
 
   bool allow_cross_origin_auth_prompt_;
 
+  // stale-while-revalidate is enabled either via experiment or command-line
+  // flag.
+  bool async_revalidation_enabled_;
+
+  // Async revalidations that are currently in-flight: either waiting to be
+  // scheduled or active on the network.
+  AsyncRevalidationMap in_progress_async_revalidations_;
+
   // http://crbug.com/90971 - Assists in tracking down use-after-frees on
   // shutdown.
   std::set<const ResourceContext*> active_resource_contexts_;