[Android] Delete local java reference every loop.
In ForeignSessionHelper class, there were two places
we allocate ScopedJavaLocalRef<jstring> inside a loop and
doesn't delete. The Java local references are cleaned upon
returning to Java, but there is 512 local reference hard-limit
so we should delete it every loop to avoid hitting the limit.
BUG=366659
Review URL: https://codereview.chromium.org/
257513007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266398 0039d316-1c4b-4281-b951-d872f2087c98