Send replies to sync IPCs from swapped out renderers.

content/common/swapped_out_messages.cc

Index: content/common/swapped_out_messages.cc
diff --git a/content/common/swapped_out_messages.cc b/content/common/swapped_out_messages.cc
index 3189d19f7f7cc5aaedbbc20b856610c33aabc249..55cec7ca258a21a4cb2cef5d2c0698342411d279 100644
--- a/content/common/swapped_out_messages.cc
+++ b/content/common/swapped_out_messages.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -35,6 +35,12 @@ bool SwappedOutMessages::CanSendWhileSwappedOut(const IPC::Message* msg) {
 
 bool SwappedOutMessages::CanHandleWhileSwappedOut(
     const IPC::Message& msg) {
+  // We must allow all synchronous IPC messages to be processed, or else
+  // the renderer process will become stuck and won't respond to future
+  // navigations.
+  if (msg.is_sync())
+    return true;
+
   // Any message the renderer is allowed to send while swapped out should
   // be handled by the browser.
   if (CanSendWhileSwappedOut(&msg))