Let CueTimeline::currentlyActiveCues() return by reference-to-const

CueList is a Vector<CueInterval>, so passing it by value creates a copy.
This was verified in a debugger.

BUG=321654

Review URL: https://codereview.chromium.org/1014873004

git-svn-id: svn://svn.chromium.org/blink/trunk@192144 bbb929c8-8fbe-4397-9dbb-9b2b20218538
2 files changed
tree: aa98d9d331448005bd96f265dc4e904b66545d8f
  1. third_party/