framework/av: Check for NULL pointer of mCblk and zero division error

latency calculation happens in two places: AudioTrack::latency() and
AudioTrack::dump(). Need to add null pointer and zero division check on
both of these places.

Change-Id: I9cbe8c1c00a390cd626bdbf202124f27e60eb3e3
Fixed-CRs: 548514

Conflicts:
	media/libmedia/AudioTrack.cpp
audioflinger: do not use raw pointer for tracks

Commit 9da3d95 surfaced a problem caused by the use of a raw
pointer to a track in offload thread implementation.

Pointers to tracks should always be weak or strong pointers.

Bug: 11708529.
Change-Id: Ic48632532d186c9be8261f73cefdf824b9fbbd2b
audioflinger: SRS effects are not working for LPA

    -Issue: If SRS effects are applied on LPA playback,
     in ARM side there is a delay of 4-5 seconds for effects
     application
    -Root cause: In applyEffects SRS effects are applied first and
     then Android effects are applied.
     In case of active android effects, SRS effects are called
     first and then android effects are called, so buffer with
     SRS effects is getting overwritten with buffer with
     android effects.
     If there are no android effects applied then all
     the SRS effects are overwritten with decoded data.
     So until next write call, SRS effects are not applied and hence delay
     of 4-5 seconds
    -Fix: In applyEffects first apply android effects and then
     apply SRS effects

Change-Id: I36b2133256d168f06b13c3d4a2bad00312d571ac
CRs-Fixed: 566278

Conflicts:
	services/audioflinger/Effects.cpp
audio: Supress redundant effect config events in short duration

Distortion sound persists for the whole song when re-enabling effect in
LPA playback mode till switch to next song. And pop noise is quite obvious
when enable/disable effects in LPA.

As the design of LPA, EffectsThreadEntry() loop is used to handle effect
config changes through applying effects with new config on dsp pcm buffers.
However, it can't handle too many config change events in a short time,
and effect with new configuration will be applied on part of dsp buffers.

Filter out redundant effect config events that come too closely to avoid
applying effect on dsp buffer in vain.

Change-Id: If8915b1d068724d5976e1519ec57e3c08cf89c9d
CRs-Fixed: 562806, 563418
framework/av: Fix for frame drop in video playback

- Breaks in video playback seen in video clips having audio content
  with sampling rates less than 16kHz.
- While extrapolating real time with system time, the real time is wrongly
  caped.
- Fix this issue by limiting the extrapolated real time only when EOS
  is reached.

Change-Id: I95b6a8f7f1f1fd561c92955cf52151ae2890c9a7
CRs-Fixed: 400398

Conflicts:
	media/libstagefright/AudioPlayer.cpp
audioflinger: Add Null pointer check while enabling effects for LPA

- MediaServer is crashing when disabling effects after mediaplayer
object is released.
- EffectChain pointer is de-referenced without NULL check, hence
leading to a mediaserver crash.
- Adding a NULL pointer check before using EffectChain object.

Change-Id: If5ff469445246028046ba65e5ddf3300180318c2
CRs-Fixed: 583305

Conflicts:
	services/audioflinger/Effects.cpp
Audio: Tunnel Exception for ER AAC ELD profile format

- some m4a clips are not working properly

- ADSP audio decoders don't support ER AAC ELD support

- Added tunnel exception for ER AAC ELD format.
  Added AACProfile metadata support for MKVExtractor

Change-Id: I2f6fe721b05377dfe0f24ea0ad1f6c4a885d576d

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
audio: Check the return code of MediaWriter::start

- Return code of MediaWriter::start method is not checked
  in startRawAudioRecording. Due to this, sound recorder
  application is not receiving the error whenever there is
  an error in starting of the recording
- Fix is to check the error and return it back to
  the client accordingly

Change-Id: I15916211da7a2eb0f27fbf9d4151410a8bdfdd42
CRs-Fixed: 591788
audio: Use composition instead of multiple inheritance

- AudioTrack is derived from BnDirectTrackClient along
  with RefBase to receive the notifications from
  AudioFlinger in tunnel/LPA mode. This is breaking
  binary compatibility for the clients which use native
  AudioTrack directly instead of Java based AudioTrack
  API
- Fix is to use composition here instead of inheritance

Change-Id: I9fd2c61cff5629924e3b08f63559679e0263bcfd

Conflicts:
	media/libmedia/AudioTrack.cpp