Use chromium_org from CM repos

Change-Id: I492d8a3792be501b23ff56d1f92b053eb7752dc7
android-5.0.0_r2 -> android-5.0.0_r6

Change-Id: I3b1ed33ec528cec179eb4e3fd960e302db8bcc5a
Import Qualcomm SELinux policy by default

Change-Id: I6bcccb145af56e33a3c6ece210542951e09fa010