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, 30 insertions, 22 deletions

diff --git a/net/url_request/url_request_job.cc b/net/url_request/url_request_job.cc
index 797caa6..f9043cc 100644
--- a/net/url_request/url_request_job.cc
+++ b/net/url_request/url_request_job.cc
@@ -6,7 +6,6 @@
 
 #include "base/message_loop.h"
 #include "base/string_util.h"
-#include "googleurl/src/gurl.h"
 #include "net/base/auth.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
@@ -30,6 +29,7 @@ URLRequestJob::URLRequestJob(URLRequest* request)
       read_buffer_len_(0),
       has_handled_response_(false),
       expected_content_size_(-1),
+      deferred_redirect_status_code_(-1),
       packet_timing_enabled_(false),
       filter_input_byte_count_(0),
       bytes_observed_in_packets_(0),
@@ -103,6 +103,17 @@ void URLRequestJob::ContinueDespiteLastError() {
   NOTREACHED();
 }
 
+void URLRequestJob::FollowDeferredRedirect() {
+  DCHECK(deferred_redirect_status_code_ != -1);
+  // NOTE: deferred_redirect_url_ may be invalid, and attempting to redirect to
+  // such an URL will fail inside FollowRedirect.  The DCHECK above asserts
+  // that we called OnReceivedRedirect.
+
+  FollowRedirect(deferred_redirect_url_, deferred_redirect_status_code_);
+  deferred_redirect_url_ = GURL();
+  deferred_redirect_status_code_ = -1;
+}
+
 int64 URLRequestJob::GetByteReadCount() const {
   return filter_input_byte_count_;
 }
@@ -175,6 +186,14 @@ bool URLRequestJob::ReadRawDataForFilter(int *bytes_read) {
   return rv;
 }
 
+void URLRequestJob::FollowRedirect(const GURL& location, int http_status_code) {
+  g_url_request_job_tracker.OnJobRedirect(this, location, http_status_code);
+
+  int rv = request_->Redirect(location, http_status_code);
+  if (rv != net::OK)
+    NotifyDone(URLRequestStatus(URLRequestStatus::FAILED, rv));
+}
+
 void URLRequestJob::FilteredDataRead(int bytes_read) {
   DCHECK(filter_.get());  // don't add data if there is no filter
   filter_->FlushStreamBuffer(bytes_read);
@@ -322,8 +341,8 @@ void URLRequestJob::NotifyHeadersComplete() {
   // survival until we can get out of this method.
   scoped_refptr<URLRequestJob> self_preservation = this;
 
-  int http_status_code;
   GURL new_location;
+  int http_status_code;
   if (IsRedirectResponse(&new_location, &http_status_code)) {
     const GURL& url = request_->url();
 
@@ -338,19 +357,21 @@ void URLRequestJob::NotifyHeadersComplete() {
       new_location = new_location.ReplaceComponents(replacements);
     }
 
-    // Toggle this flag to true so the consumer can access response headers.
-    // Then toggle it back if we choose to follow the redirect.
-    has_handled_response_ = true;
-    request_->ReceivedRedirect(new_location);
+    bool defer_redirect = false;
+    request_->ReceivedRedirect(new_location, &defer_redirect);
 
     // Ensure that the request wasn't detached or destroyed in ReceivedRedirect
     if (!request_ || !request_->delegate())
       return;
 
-    // If we were not cancelled, then follow the redirect.
+    // If we were not cancelled, then maybe follow the redirect.
     if (request_->status().is_success()) {
-      has_handled_response_ = false;
-      FollowRedirect(new_location, http_status_code);
+      if (defer_redirect) {
+        deferred_redirect_url_ = new_location;
+        deferred_redirect_status_code_ = http_status_code;
+      } else {
+        FollowRedirect(new_location, http_status_code);
+      }
       return;
     }
   } else if (NeedsAuth()) {
@@ -507,19 +528,6 @@ bool URLRequestJob::FilterHasData() {
     return filter_.get() && filter_->stream_data_len();
 }
 
-void URLRequestJob::FollowRedirect(const GURL& location,
-                                   int http_status_code) {
-  g_url_request_job_tracker.OnJobRedirect(this, location, http_status_code);
-  Kill();
-  // Kill could have notified the Delegate and destroyed the request.
-  if (!request_)
-    return;
-
-  int rv = request_->Redirect(location, http_status_code);
-  if (rv != net::OK)
-    NotifyStartError(URLRequestStatus(URLRequestStatus::FAILED, rv));
-}
-
 void URLRequestJob::RecordBytesRead(int bytes_read) {
   if (is_profiling()) {
     ++(metrics_->number_of_read_IO_);