Allow the NetworkDelegate to synchronously cancel a URLRequest.

BUG=49612
TEST=net_unittests:URLRequestTestHTTP.NetworkDelegateCancelRequestSynchronously


Review URL: http://codereview.chromium.org/7747016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98978 0039d316-1c4b-4281-b951-d872f2087c98

net/url_request/url_request.cc

@@ -403,11 +403,17 @@ void URLRequest::Start() {
 
   // Only notify the delegate for the initial request.
   if (context_ && context_->network_delegate()) {
-    if (context_->network_delegate()->NotifyBeforeURLRequest(
-            this, &before_request_callback_, &delegate_redirect_url_) ==
-            net::ERR_IO_PENDING) {
-      SetBlockedOnDelegate();
-      return;  // paused
+    int error = context_->network_delegate()->NotifyBeforeURLRequest(
+        this, &before_request_callback_, &delegate_redirect_url_);
+    if (error != net::OK) {
+      if (error == net::ERR_IO_PENDING) {
+        // Paused on the delegate, will invoke |before_request_callback_| later.
+        SetBlockedOnDelegate();
+      } else {
+        // The delegate immediately returned some error code.
+        BeforeRequestComplete(error);
+      }
+      return;
     }
   }
 
@@ -420,7 +426,8 @@ void URLRequest::BeforeRequestComplete(int error) {
   DCHECK(!job_);
   DCHECK_NE(ERR_IO_PENDING, error);
 
-  SetUnblockedOnDelegate();
+  if (blocked_on_delegate_)
+    SetUnblockedOnDelegate();
   if (error != OK) {
     net_log_.AddEvent(NetLog::TYPE_CANCELLED,
         make_scoped_refptr(new NetLogStringParameter("source", "delegate")));

net/url_request/url_request_unittest.cc

@@ -123,9 +123,11 @@ void CheckSSLInfo(const SSLInfo& ssl_info) {
 class BlockingNetworkDelegate : public TestNetworkDelegate {
  public:
   BlockingNetworkDelegate()
-      : callback_retval_(net::OK),
+      : retval_(net::ERR_IO_PENDING),
+        callback_retval_(net::OK),
         ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {}
 
+  void set_retval(int retval) { retval_ = retval; }
   void set_callback_retval(int retval) { callback_retval_ = retval; }
   void set_redirect_url(const GURL& url) { redirect_url_ = url; }
 
@@ -143,6 +145,10 @@ class BlockingNetworkDelegate : public TestNetworkDelegate {
 
     if (!redirect_url_.is_empty())
       *new_url = redirect_url_;
+
+    if (retval_ != net::ERR_IO_PENDING)
+      return retval_;
+
     MessageLoop::current()->PostTask(
         FROM_HERE,
         method_factory_.NewRunnableMethod(&BlockingNetworkDelegate::DoCallback,
@@ -154,6 +160,7 @@ class BlockingNetworkDelegate : public TestNetworkDelegate {
     callback->Run(callback_retval_);
   }
 
+  int retval_;
   int callback_retval_;
   GURL redirect_url_;
   ScopedRunnableMethodFactory<BlockingNetworkDelegate> method_factory_;
@@ -343,6 +350,34 @@ TEST_F(URLRequestTestHTTP, NetworkDelegateCancelRequest) {
   EXPECT_EQ(1, network_delegate.destroyed_requests());
 }
 
+// Tests that the network delegate can cancel a request synchronously.
+TEST_F(URLRequestTestHTTP, NetworkDelegateCancelRequestSynchronously) {
+  ASSERT_TRUE(test_server_.Start());
+
+  TestDelegate d;
+  BlockingNetworkDelegate network_delegate;
+  network_delegate.set_retval(ERR_EMPTY_RESPONSE);
+
+  scoped_refptr<TestURLRequestContext> context(new TestURLRequestContext(true));
+  context->SetProxyFromString(test_server_.host_port_pair().ToString());
+  context->set_network_delegate(&network_delegate);
+  context->Init();
+
+  {
+    TestURLRequest r(test_server_.GetURL(""), &d);
+    r.set_context(context);
+
+    r.Start();
+    MessageLoop::current()->Run();
+
+    EXPECT_EQ(URLRequestStatus::FAILED, r.status().status());
+    EXPECT_EQ(ERR_EMPTY_RESPONSE, r.status().os_error());
+    EXPECT_EQ(1, network_delegate.created_requests());
+    EXPECT_EQ(0, network_delegate.destroyed_requests());
+  }
+  EXPECT_EQ(1, network_delegate.destroyed_requests());
+}
+
 // Tests that the network delegate can block and redirect a request to a new
 // URL.
 TEST_F(URLRequestTestHTTP, NetworkDelegateRedirectRequest) {