Use chromium_org from CM repos

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

Change-Id: I3b1ed33ec528cec179eb4e3fd960e302db8bcc5a
Merge remote-tracking branch 'cyanogenmod/cm-12.0' into cm-12.0