libstagefright: Check for duration > 0 to avoid DivideByZero crash

- duration = 0 can cause divide by zero and for this clip duration
  is indiacted as 0.
- check for duration > 0 rather than duration >= 0

Change-Id: I58ccacbf7ede892dff9626715162ea7b1f2ddbc6
CRs-Fixed: 451855
audioflinger: Fix to set correct volume in Tunnel playback

- After a pause and resume, tunnel playback volume is always
  set to maximum irrespective of the volume value before pause.
- The cause for this is, the stream volume is not used to set
  the volume in directaudiotrack.
- Fix is to use the stream volume to set volume during tunnel
  playback.

Change-Id: I59cda146ed88bd5c4186aeb9ae5d165f4a27493f
CRs-fixed: 452285
libstagefright: Add support for frame-by-frame mode

- Set decoder in frame-by-frame mode always, except for interlaced
  content, for which arbitary mode should be set

Change-Id: I8195a40549898b43a0e03d65663c7148f458c448
ACodec: Support for dynamic port reconfig

- On port settings changed first flush output port
- Move ACodec to new state called FlushingOutputState
- Flush all output buffers, wait till all decoded buffers
  are rendered
- Then disable output port, and allocate output buffers
  with new resolution, and reset native window

Change-Id: Iafa266371ed2a87b909fbcb4eeae6b64208df617
libmediaplayerservice: Add new player for DASH

- Add new player factory to support dash playback.
- DASH urls end with .mpd. When media player receives
  an url with .mpd, it will use new factory to instantiate the player
  to be used for supporting DASH playback.

Change-Id: I69e5a08fb2baf89d97b1e0711dbe52a8b1c39c29