Remove Loadable.isLoadCanceled

This simplifies Loadable implementations, and also removes the
possibility of an incorrect Loadable implementation causing the
wrong Loader.Callback method being called (perviously, for the
correct method to be called, we relied on isLoadCanceled being
implemented correctly).

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=198871133

library/core/src/main/java/com/google/android/exoplayer2/source/ExtractorMediaPeriod.java

@@ -832,11 +832,6 @@ import java.util.Arrays;
       loadCanceled = true;
     }
 
-    @Override
-    public boolean isLoadCanceled() {
-      return loadCanceled;
-    }
-
     @Override
     public void load() throws IOException, InterruptedException {
       int result = Extractor.RESULT_CONTINUE;

library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaPeriod.java

@@ -348,11 +348,6 @@ import java.util.Arrays;
       // Never happens.
     }
 
-    @Override
-    public boolean isLoadCanceled() {
-      return false;
-    }
-
     @Override
     public void load() throws IOException, InterruptedException {
       // We always load from the beginning, so reset the sampleSize to 0.

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/ContainerMediaChunk.java

@@ -106,11 +106,6 @@ public class ContainerMediaChunk extends BaseMediaChunk {
     loadCanceled = true;
   }
 
-  @Override
-  public final boolean isLoadCanceled() {
-    return loadCanceled;
-  }
-
   @SuppressWarnings("NonAtomicVolatileUpdate")
   @Override
   public final void load() throws IOException, InterruptedException {

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/DataChunk.java

@@ -75,11 +75,6 @@ public abstract class DataChunk extends Chunk {
     loadCanceled = true;
   }
 
-  @Override
-  public final boolean isLoadCanceled() {
-    return loadCanceled;
-  }
-
   @Override
   public final void load() throws IOException, InterruptedException {
     try {

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/InitializationChunk.java

@@ -69,11 +69,6 @@ public final class InitializationChunk extends Chunk {
     loadCanceled = true;
   }
 
-  @Override
-  public boolean isLoadCanceled() {
-    return loadCanceled;
-  }
-
   @SuppressWarnings("NonAtomicVolatileUpdate")
   @Override
   public void load() throws IOException, InterruptedException {

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/SingleSampleMediaChunk.java

@@ -34,7 +34,6 @@ public final class SingleSampleMediaChunk extends BaseMediaChunk {
   private final Format sampleFormat;
 
   private volatile int bytesLoaded;
-  private volatile boolean loadCanceled;
   private volatile boolean loadCompleted;
 
   /**
@@ -90,12 +89,7 @@ public final class SingleSampleMediaChunk extends BaseMediaChunk {
 
   @Override
   public void cancelLoad() {
-    loadCanceled = true;
+    // Do nothing.
-  }
-
-  @Override
-  public boolean isLoadCanceled() {
-    return loadCanceled;
   }
 
   @SuppressWarnings("NonAtomicVolatileUpdate")

library/core/src/main/java/com/google/android/exoplayer2/upstream/Loader.java

@@ -57,11 +57,6 @@ public final class Loader implements LoaderErrorThrower {
      */
     void cancelLoad();
 
-    /**
-     * Returns whether the load has been canceled.
-     */
-    boolean isLoadCanceled();
-
     /**
      * Performs the load, returning on completion or cancellation.
      *
@@ -260,6 +255,7 @@ public final class Loader implements LoaderErrorThrower {
     private int errorCount;
 
     private volatile Thread executorThread;
+    private volatile boolean canceled;
     private volatile boolean released;
 
     public LoadTask(Looper looper, T loadable, Loader.Callback<T> callback,
@@ -296,6 +292,7 @@ public final class Loader implements LoaderErrorThrower {
           sendEmptyMessage(MSG_CANCEL);
         }
       } else {
+        canceled = true;
         loadable.cancelLoad();
         if (executorThread != null) {
           executorThread.interrupt();
@@ -317,7 +314,7 @@ public final class Loader implements LoaderErrorThrower {
     public void run() {
       try {
         executorThread = Thread.currentThread();
-        if (!loadable.isLoadCanceled()) {
+        if (!canceled) {
           TraceUtil.beginSection("load:" + loadable.getClass().getSimpleName());
           try {
             loadable.load();
@@ -334,7 +331,7 @@ public final class Loader implements LoaderErrorThrower {
         }
       } catch (InterruptedException e) {
         // The load was canceled.
-        Assertions.checkState(loadable.isLoadCanceled());
+        Assertions.checkState(canceled);
         if (!released) {
           sendEmptyMessage(MSG_END_OF_SOURCE);
         }
@@ -379,7 +376,7 @@ public final class Loader implements LoaderErrorThrower {
       finish();
       long nowMs = SystemClock.elapsedRealtime();
       long durationMs = nowMs - startTimeMs;
-      if (loadable.isLoadCanceled()) {
+      if (canceled) {
         callback.onLoadCanceled(loadable, nowMs, durationMs, false);
         return;
       }

library/core/src/main/java/com/google/android/exoplayer2/upstream/ParsingLoadable.java

@@ -78,7 +78,6 @@ public final class ParsingLoadable<T> implements Loadable {
   private final Parser<? extends T> parser;
 
   private volatile T result;
-  private volatile boolean isCanceled;
   private volatile long bytesLoaded;
 
   /**
@@ -128,14 +127,7 @@ public final class ParsingLoadable<T> implements Loadable {
 
   @Override
   public final void cancelLoad() {
-    // We don't actually cancel anything, but we need to record the cancellation so that
+    // Do nothing.
-    // isLoadCanceled can return the correct value.
-    isCanceled = true;
-  }
-
-  @Override
-  public final boolean isLoadCanceled() {
-    return isCanceled;
   }
 
   @Override

library/core/src/test/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelectionTest.java

@@ -391,11 +391,6 @@ public final class AdaptiveTrackSelectionTest {
       // Do nothing.
     }
 
-    @Override
-    public boolean isLoadCanceled() {
-      return false;
-    }
-
     @Override
     public void load() throws IOException, InterruptedException {
       // Do nothing.

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaChunk.java

@@ -206,11 +206,6 @@ import java.util.concurrent.atomic.AtomicInteger;
     loadCanceled = true;
   }
 
-  @Override
-  public boolean isLoadCanceled() {
-    return loadCanceled;
-  }
-
   @Override
   public void load() throws IOException, InterruptedException {
     maybeLoadInitData();