Identify service worker version at main resource load time.

content/child/request_extra_data.h

 // Copyright (c) 2012 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 CONTENT_CHILD_REQUEST_EXTRA_DATA_H_
 #define CONTENT_CHILD_REQUEST_EXTRA_DATA_H_
 
 #include "base/compiler_specific.h"
 #include "content/common/content_export.h"
 #include "content/public/common/page_transition_types.h"
 #include "third_party/WebKit/public/web/WebPageVisibilityState.h"
 #include "webkit/child/weburlrequest_extradata_impl.h"
 
 namespace content {
 
-// The RenderView stores an instance of this class in the "extra data" of each
-// ResourceRequest (see RenderFrameImpl::willSendRequest).
+// The RenderView and EmbeddedWorkerContextClient store an instance of this
+// class in the "extra data" of each ResourceRequest (see the willSendRequest
+// methods of RenderFrameImpl and EmbeddedWorkerContextClient willSendRequest).
 class CONTENT_EXPORT RequestExtraData
     : NON_EXPORTED_BASE(public webkit_glue::WebURLRequestExtraDataImpl) {
  public:
+  RequestExtraData();
+  explicit RequestExtraData(int service_worker_provider_id);

[dcheng, 2014/03/17 22:12:10]

I'm not a huge fan of the constructor from int, since there are a number of
other int fields and it's not particularly obvious to me that a constructor from
int "should" be a service worker provider id.

[michaeln, 2014/03/17 22:53:58]

I'd chose this instead of a public setter for just that single data member. I'd
be fine with changing this around to cons up a RequestExtraData struct with just
that one field set differently then the defaults. Did you have anything
particular in mind?

   RequestExtraData(blink::WebPageVisibilityState visibility_state,
                    const blink::WebString& custom_user_agent,
                    bool was_after_preconnect_request,
                    int render_frame_id,
                    bool is_main_frame,
                    const GURL& frame_origin,
                    bool parent_is_main_frame,
                    int parent_render_frame_id,
                    bool allow_download,
                    PageTransition transition_type,
@@ skipping 39 matching lines @@
   int transferred_request_child_id_;
   int transferred_request_request_id_;
   int service_worker_provider_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestExtraData);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_REQUEST_EXTRA_DATA_H_