URLFetcher: Skip posting to IO thread if already on IO thread.

BUG=123224
TEST=none


Review URL: http://codereview.chromium.org/10105018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132539 0039d316-1c4b-4281-b951-d872f2087c98

content/common/net/url_fetcher_core.cc

@@ -331,7 +331,11 @@ void URLFetcherCore::Stop() {
 
   delegate_ = NULL;
   fetcher_ = NULL;
-  if (io_message_loop_proxy_.get()) {
+  if (!io_message_loop_proxy_.get())
+    return;
+  if (io_message_loop_proxy_->RunsTasksOnCurrentThread()) {
+    CancelURLRequest();
+  } else {
     io_message_loop_proxy_->PostTask(
         FROM_HERE, base::Bind(&URLFetcherCore::CancelURLRequest, this));
   }