Implement a ResourceThrottle for URL overriding in Chrome on Android.

net/url_request/url_request.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 NET_URL_REQUEST_URL_REQUEST_H_
 #define NET_URL_REQUEST_URL_REQUEST_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 519 matching lines @@
   // Cancels the request and sets the error to |error| (see net_error_list.h
   // for values).
   void CancelWithError(int error);
 
   // Cancels the request and sets the error to |error| (see net_error_list.h
   // for values) and attaches |ssl_info| as the SSLInfo for that request.  This
   // is useful to attach a certificate and certificate error to a canceled
   // request.
   void CancelWithSSLError(int error, const SSLInfo& ssl_info);
 
+  // Cancels the requests and sets the status to HANDLED_EXTERNALLY.
+  void CancelWithHandledExternallyStatus();

[darin (slow to review), 2012/05/29 23:39:32]

It looks like this may actually be moving in the wrong direction code-wise.  The
network stack really has no need to know about the HANDLED_EXTERNALLY bit.  It
is only the WebURLLoaderImpl that needs to see this bit so that the navigation
can be suppressed on the WebKit side.

I think that instead of teaching src/net/ about HANDLED_EXTERNALLY more, we
should just rip that out entirely.  We should probably remove HANDLED_EXTERNALLY
from URLRequestStatus, and we should invent a new data structure for conveying
network response status information to the WebURLLoaderImpl.

Sorry to add more work, but I think it was always a mistake to have this
HANDLED_EXTERNALLY flag defined in the network stack.  It doesn't need to know
about this flag.

+
   // Read initiates an asynchronous read from the response, and must only
   // be called after the OnResponseStarted callback is received with a
   // successful status.
   // If data is available, Read will return true, and the data and length will
   // be returned immediately.  If data is not available, Read returns false,
   // and an asynchronous Read is initiated.  The Read is finished when
   // the caller receives the OnReadComplete callback.  Unless the request was
   // cancelled, OnReadComplete will always be called, even if the read failed.
   //
   // The buf parameter is a buffer to receive the data.  If the operation
@@ skipping 127 matching lines @@
   // Restarting involves replacing the current job with a new one such as what
   // happens when following a HTTP redirect.
   void RestartWithJob(URLRequestJob* job);
   void PrepareToRestart();
 
   // Detaches the job from this request in preparation for this object going
   // away or the job being replaced. The job will not call us back when it has
   // been orphaned.
   void OrphanJob();
 
-  // Cancels the request and set the error and ssl info for this request to the
-  // passed values.
-  void DoCancel(int error, const SSLInfo& ssl_info);
+  // Cancels the request and set the status and ssl info for this request to
+  // the passed values.
+  void DoCancel(const URLRequestStatus& status, const SSLInfo& ssl_info);
 
   // Notifies the network delegate that the request has been completed.
   // This does not imply a successful completion. Also a canceled request is
   // considered completed.
   void NotifyRequestCompleted();
 
   // Called by URLRequestJob to allow interception when the final response
   // occurs.
   void NotifyResponseStarted();
 
@@ skipping 101 matching lines @@
   base::TimeTicks creation_time_;
 
   scoped_ptr<const base::debug::StackTrace> stack_trace_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequest);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_H_