Add support to URLRequest for deferring redirects.

I chose to add an out parameter to OnReceivedRedirect because it allows for the
default behavior to remain the same.

I considered adding a ContinueAfterRedirect method that all OnReceivedRedirect
implementations would need to call, but this caused one annoying problem:  In
the case of a ChromePlugin, it is possible for the URLRequest to get deleted
inside the handler for the redirect.  This would make it hard to subsequently
call a method on the URLRequest since I would need to have a way to determine
if the URLRequest had been deleted.

TEST=covered by unit tests
BUG=16413,6442
R=eroman,wtc

Review URL: http://codereview.chromium.org/155897

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21417 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 4 deletions

diff --git a/net/url_request/url_request.h b/net/url_request/url_request.h
index 5ffec08..84da0cc 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -135,10 +135,19 @@ class URLRequest {
     //
     // When this function is called, the request will still contain the
     // original URL, the destination of the redirect is provided in 'new_url'.
-    // If the request is not canceled the redirect will be followed and the
-    // request's URL will be changed to the new URL.
+    // If the delegate does not cancel the request and |*defer_redirect| is
+    // false, then the redirect will be followed, and the request's URL will be
+    // changed to the new URL.  Otherwise if the delegate does not cancel the
+    // request and |*defer_redirect| is true, then the redirect will be
+    // followed once FollowDeferredRedirect is called on the URLRequest.
+    //
+    // The caller must set |*defer_redirect| to false, so that delegates do not
+    // need to set it if they are happy with the default behavior of not
+    // deferring redirect.
     virtual void OnReceivedRedirect(URLRequest* request,
-                                    const GURL& new_url) = 0;
+                                    const GURL& new_url,
+                                    bool* defer_redirect) {
+    }
 
     // Called when we receive an authentication failure.  The delegate should
     // call request->SetAuth() with the user's credentials once it obtains them,
@@ -436,6 +445,10 @@ class URLRequest {
   // will be set to an error.
   bool Read(net::IOBuffer* buf, int max_bytes, int *bytes_read);
 
+  // This method may be called to follow a redirect that was deferred in
+  // response to an OnReceivedRedirect call.
+  void FollowDeferredRedirect();
+
   // One of the following two methods should be called in response to an
   // OnAuthRequired() callback (and only then).
   // SetAuth will reissue the request with the given credentials.
@@ -494,7 +507,7 @@ class URLRequest {
   int Redirect(const GURL& location, int http_status_code);
 
   // Called by URLRequestJob to allow interception when a redirect occurs.
-  void ReceivedRedirect(const GURL& location);
+  void ReceivedRedirect(const GURL& location, bool* defer_redirect);
 
   // Called by URLRequestJob to allow interception when the final response
   // occurs.