Add Resource Handler for creating Streams to forward to extensions

content/public/browser/resource_dispatcher_host_delegate.h

Index: content/public/browser/resource_dispatcher_host_delegate.h
diff --git a/content/public/browser/resource_dispatcher_host_delegate.h b/content/public/browser/resource_dispatcher_host_delegate.h
index 890f1c7b728f77867de115c5d85df3a2ba7a7937..eff46f666d45a742d93a87f3b509f5734ed9a441 100644
--- a/content/public/browser/resource_dispatcher_host_delegate.h
+++ b/content/public/browser/resource_dispatcher_host_delegate.h
@@ -107,6 +107,25 @@ class CONTENT_EXPORT ResourceDispatcherHostDelegate {
   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,