[Sync] Updated CookieJarMismatch to handle multiple sync cycles during OpenTabAndGetLocalWindows.

chrome/browser/sync/test/integration/sessions_helper.h

Index: chrome/browser/sync/test/integration/sessions_helper.h
diff --git a/chrome/browser/sync/test/integration/sessions_helper.h b/chrome/browser/sync/test/integration/sessions_helper.h
index bfa01297c2ad246bb9c4618517842a01a40555e9..365bc091c121cce1178e8f8c9b133fce46b2e284 100644
--- a/chrome/browser/sync/test/integration/sessions_helper.h
+++ b/chrome/browser/sync/test/integration/sessions_helper.h
@@ -33,7 +33,11 @@ bool GetLocalWindows(int index, ScopedWindowMap* local_windows);
 
 // Creates and verifies the creation of a new window for profile |index| with
 // one tab displaying |url|. Copies the SessionWindow associated with the new
-// window to |local_windows|. Returns true if successful.
+// window to |local_windows|. Returns true if successful. This call results in
+// multiple sessions changes, and performs synchronous blocking. It is rare, but
+// possible, that multiple sync cycle commits occur as a result of this call.
+// Test cases should be written to handle this possibility, otherwise they may
+// flake.
 bool OpenTabAndGetLocalWindows(int index,
                                const GURL& url,
                                ScopedWindowMap* local_windows);