SDK / exoplayer

Adds a few unused fields to HlsUrl and moves things towards the Hls
reimplementation we are looking for. Also fixes a bug related to
asuming every getNextChunk().loadable == null being related to
reaching the live edge.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132305206

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132301223

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132248872

Issue:#1772

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132078273

TsExtractor support for language code in the audio tracks.

New version hangs when running:
./gradlew :library:assembleAndroidTest --debug

Android Studio "strongly recommends" we upgrade to the
hanging version, but I guess we'll just have to ignore
that until the latest version works again!

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132063280

If the live window has a small duration, we currently
end up setting the default start position to be right
at the start of the window. This increases the chance
of a BehindLiveWindowException.

With this change we impose a minimum 5s gap between
the start of the window and the default start position.
If the window is *really* small (<10s) then doing this
would push the default start position too close to the
end of the window. We don't have much time to play with
in either direction in this case, so we put the default
start position in the middle of the window and hope for
the best.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132054802

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132053698

Now you can do cool things (if you really want to!) like
play a video twice, then play a second video, then loop
the whole thing, all seamlessly.

new LoopingMediaSource(
  new LoopingMediaSource(firstVideoSource, 2),
  secondVideoSource));

You can also just loop, which is probably more useful :).

Issue: #490

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132049599

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132049545

People will inevitably try and do it, and it's pretty
easy to handle properly, so why not...

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132047019

- Don't send a timeline to the listener until all children
  have reported their timelines.
- Propagate a proper merge error if merging fails.
- The PlayerActivity hack is necessary due to the way Andorid's
  MediaController widget attaches to the window :(. It'll go
  away once we get our own player controls.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131958169

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131946543

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131931868

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131931668

This could cause us to "lose" allocations backed by an
initial block, meaning they became unavailable for use
despite still being allocated.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131931465

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131931329

- Centralise compileSdkVersion, targetSdkVersion and
  buildToolsVersion in a single place for gradle.
- Bump compileSdkVersion and targetSdkVersion to 24.
- Bump com.android.tools.build version to re-enable
  instant start.
- Bump targetSdkVersion in manifests (needed for
  internal builds).
- Use standard expandable_list_item from Android in
  the demo app, since ours doesn't look right when
  targeting API level 24. We were also setting the
  theme on the wrong element in the manifest, so I'm
  removing that line.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131929216

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131853683

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131843222

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131825185

Issue:#1772

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131812670

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131810070

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131731376

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131715194

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131714051

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131696858

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131693969

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131693379

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131692317

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131534334

- The need to pass a Clock is pretty much only for testing, so
  make the constructor that takes one package private + use
  the system clock for public constructors.
- Add default timeout values.
- Also make sure we set Content-Type in all license requests,
  since when using Cronet the stack requires it to be set.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131404298

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131398594

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131398162

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131394778

This is done through the bitstream id field and allows removing
the isEac3 parameter from the constructor.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131393477

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131393395