Add int params to URLDataSource::StartDataRequest().

content/public/browser/url_data_source.h

 // Copyright (c) 2013 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_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 #define CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 25 matching lines @@
 
   // The name of this source.
   // E.g., for favicons, this could be "favicon", which results in paths for
   // specific resources like "favicon/34" getting sent to this source.
   virtual std::string GetSource() = 0;
 
   // Used by StartDataRequest so that the child class can return the data when
   // it's available.
   typedef base::Callback<void(base::RefCountedMemory*)> GotDataCallback;
 
+  // Request fields passed to StartDataRequest in addition to the path.
+  struct ExtraRequestInfo {
+    bool is_incognito;
+    int render_process_id;
+    int render_view_id;
+  };
+
   // Called by URLDataSource to request data at |path|. The string parameter is
   // the path of the request. The child class should run |callback| when the
   // data is available or if the request could not be satisfied. This can be
   // called either in this callback or asynchronously with the response.
   virtual void StartDataRequest(const std::string& path,
-                                bool is_incognito,
+                                const ExtraRequestInfo& info,

[jam, 2013/04/16 23:15:30]

Per the conventions for the Content API
(http://www.chromium.org/developers/content-module/content-api), each
struct/class/enum should be in a separate file. we also try to minimize the
number of files, so I would avoid the struct. this is made easier since
"is_incognito" is now redundant if you pass in the render_process_id and
render_view_is: one can figure out incognito by doing
RenderProcessHost::FromID(render_process_id)->GetBrowserContext()->IsOffTheRecord()

it looks like only 3 of the URLDataSource implementations use this boolean, so
it's pretty easy to convert them to the above.

[Jered, 2013/04/16 23:48:15]

One of the callees who wants to check is_incognito is on the IO thread, but
RenderProcessHost::FromID is only allowed on the UI thread. That caller is just
doing a DCHECK, and I think I can convince the owner to remove it (it's Instant
code); but what would you prefer?

                                 const GotDataCallback& callback) = 0;
 
   // Return the mimetype that should be sent with this response, or empty
   // string to specify no mime type.
   virtual std::string GetMimeType(const std::string& path) const = 0;
 
   // The following methods are all called on the IO thread.
 
   // Returns the MessageLoop on which the delegate wishes to have
   // StartDataRequest called to handle the request for |path|. The default
@@ skipping 42 matching lines @@
   // Override in specific WebUI data sources to enable for additional schemes or
   // to implement fancier access control.  Typically used in concert with
   // ContentBrowserClient::GetAdditionalWebUISchemes() to permit additional
   // WebUI scheme support for an embedder.
   virtual bool ShouldServiceRequest(const net::URLRequest* request) const;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_