SDK / exoplayer

As multi period DASH isn't supported yet use the duration of the first period only.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127086808

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127073630

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127073328

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127073129

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127065122

SampleSourceProvider -> MediaSource
SampleSource -> MediaPeriod
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126914964

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126913487

Also make filterHdVideoTracks override setMaxVideoSize.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126904080

Issue: #377
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126901901

- The package is renamed to avoid conflicts with v1, should any
app wish to include both v1 and v2 for a period of time. This is
similar to the approach used by some other open source projects
(e.g. okhttp).
- Copyright year is updated everywhere for completeness.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126895326

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126888556

Before this change, calling seekTo then setPlayWhenReady would cause the player
throw an error, due to using the sample source provider before it's set.

Transition to the buffering state in seekToInternal only if we have a sample
source provider.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126804528

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126799524

1. Suppress onContinueLoadingRequested until a source is
   prepared (since such calls are not supposed to be made
   until after preparation has completed).
2. Don't use the format evaluator in HlsChunkSource prior
   to prepration completing.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126794616

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126792706

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126792535

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126790829

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126789395

Also fixed language comparison using Locale's.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126703125

Also attempt to clear up naming a little, using "buffering" to
mean the user visible buffering state, and "loading" to mean a
source being loaded.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126693592

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126691912

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126682871

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126672854

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126646585

This fixes HlsChunkSource to allow selection of variants
other than the first one (as originally ordered in the
master playlist) in the case that the first one is
blacklisted. Having done this, the two disabled tests can
be restored.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126646547

Also fix possible repeat-preparation for HlsTrackStreamWrapper
and ExtractorSampleSource.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126640380

At a high level, everything that we need to load in sync
with anything else now implements a new SequenceableLoader
class. This includes ChunkTrackStream, since multiple
demuxed tracks in DASH/SS need to be loaded in sync with
one another. At a higher level, SampleSources are also
SequenceableLoaders, which allows them to be kept in sync
by MultiSampleSource.

CompositeSequenceableLoader is able to load multiple
instances SequenceableLoaders in sync with one another,
and is used in various places where this is required.

This change also removes LoadControl registration, which
was complicated and error prone.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126632861

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126631393

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126622342

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126324788

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126306436

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126286809

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126202210

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126196431

This is causing getTrackIndex to fail for live playbacks.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126189387

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126175948

- Removes the load delay that was previously present after
  source preparation.
- Prevents premature failure in the case that the buffering
  source fails to prepare.
- SampleSource.Callback will get a second method in a
  subsequent CL, approximately meaning "tell me if I can load
  more stuff". This will remove the need for LoadControl and
  the complexity that comes with it.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126172573

This is required for buffering to work properly across
playlist transitions. It's also much simpler, since
specifying the buffering policy becomes independent of
the type of media being played (i.e. the source).
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=126051755

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125951381

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125698923