Only clears the unblock flag on sync IPCs during other sync dispatches

BUG=22210 (this is not a partial mitigation, not a fix)

Review URL: http://codereview.chromium.org/399043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@32397 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/plugin/plugin_channel.cc b/chrome/plugin/plugin_channel.cc
index be8e5f9..44779a80 100644
--- a/chrome/plugin/plugin_channel.cc
+++ b/chrome/plugin/plugin_channel.cc
@@ -161,7 +161,7 @@
       in_send_(0),
       off_the_record_(false),
       filter_(new MessageFilter()) {
-  SendUnblockingOnlyDuringDispatch();
+  SendUnblockingOnlyDuringSyncDispatch();
   ChildProcess::current()->AddRefProcess();
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   log_messages_ = command_line->HasSwitch(switches::kLogPluginMessages);