Add Resource Handler for creating Streams to forward to extensions

content/public/browser/resource_dispatcher_host_delegate.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_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 89 matching lines @@
   // guarantee that the app successfully handled it.
   virtual bool HandleExternalProtocol(const GURL& url,
                                       int child_id,
                                       int route_id);
 
   // Returns true if we should force the given resource to be downloaded.
   // Otherwise, the content layer decides.
   virtual bool ShouldForceDownloadResource(
       const GURL& url, const std::string& mime_type);
 
+  // Returns true and sets |security_origin| and |target_id| if a Stream should
+  // be created for the resource.

[darin (slow to review), 2013/03/16 17:23:51]

please document the fact that OnStreamCreated will be called if
ShouldInterceptResourceAsStream returns true.  also, document the fact that the
target_id parameter here will be forwarded to OnStreamCreated.  you might want
to explain what security_origin means in this context.

I think you should be really clear about the fact that this creates a Blob URL
associated with the given security_origin, and indicate that the Blob URL may
only be loaded once.

What happens if the Blob URL is never loaded?  Do we leak the stream data
forever?

[Zachary Kuznia, 2013/03/17 01:30:33]

I expanded these comments to explain this behavior.  I also added a 5 minute
read timeout to stream.{cc,h}.  Now, if the Stream spends more than 5 minutes
without a read observer, it unregisters itself and informer the WriteObserver
that it timed out.

+  virtual bool ShouldInterceptResourceAsStream(
+      content::ResourceContext* resource_context,
+      const GURL& url,
+      const std::string& mime_type,
+      GURL* security_origin,
+      std::string* target_id);
+
+  // Informs the delegate that a stream was created.
+  virtual void OnStreamCreated(
+      content::ResourceContext* resource_context,
+      int render_process_id,
+      int render_view_id,
+      const std::string& target_id,
+      const GURL& stream_url,
+      const std::string& mime_type,
+      const GURL& original_url);
+
   // Informs the delegate that a response has started.
   virtual void OnResponseStarted(
       net::URLRequest* request,
       ResourceContext* resource_context,
       ResourceResponse* response,
       IPC::Sender* sender);
 
   // Informs the delegate that a request has been redirected.
   virtual void OnRequestRedirected(
       const GURL& redirect_url,
       net::URLRequest* request,
       ResourceContext* resource_context,
       ResourceResponse* response);
 
  protected:
   ResourceDispatcherHostDelegate();
   virtual ~ResourceDispatcherHostDelegate();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_