FlacJni: Add exceptions to jni methods' definitions.

These methods call read(...) method which may throw these exceptions.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=124332828

extensions/flac/src/main/java/com/google/android/exoplayer/ext/flac/FlacDecoder.java

@@ -20,6 +20,7 @@ import com.google.android.exoplayer.extensions.SimpleDecoder;
 import com.google.android.exoplayer.extensions.SimpleOutputBuffer;
 import com.google.android.exoplayer.util.FlacStreamInfo;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.List;
 
@@ -52,7 +53,13 @@ import java.util.List;
 
     ByteBuffer metadata = ByteBuffer.wrap(initializationData.get(0));
     decoder.setData(metadata);
-    FlacStreamInfo streamInfo = decoder.decodeMetadata();
+    FlacStreamInfo streamInfo;
+    try {
+      streamInfo = decoder.decodeMetadata();
+    } catch (IOException | InterruptedException e) {
+      // Never happens.
+      throw new IllegalStateException(e);
+    }
     if (streamInfo == null) {
       throw new FlacDecoderException("Metadata decoding failed");
     }
@@ -84,7 +91,13 @@ import java.util.List;
     }
     decoder.setData(inputBuffer.data);
     ByteBuffer outputData = outputBuffer.init(inputBuffer.timeUs, maxOutputBufferSize);
-    int result = decoder.decodeSample(outputData);
+    int result;
+    try {
+      result = decoder.decodeSample(outputData);
+    } catch (IOException | InterruptedException e) {
+      // Never happens.
+      throw new IllegalStateException(e);
+    }
     if (result < 0) {
       return new FlacDecoderException("Frame decoding failed");
     }

extensions/flac/src/main/java/com/google/android/exoplayer/ext/flac/FlacJni.java

@@ -130,11 +130,11 @@ import java.nio.ByteBuffer;
     return byteCount;
   }
 
-  public FlacStreamInfo decodeMetadata() {
+  public FlacStreamInfo decodeMetadata() throws IOException, InterruptedException {
     return flacDecodeMetadata(nativeDecoderContext);
   }
 
-  public int decodeSample(ByteBuffer output) {
+  public int decodeSample(ByteBuffer output) throws IOException, InterruptedException {
     return output.isDirect()
         ? flacDecodeToBuffer(nativeDecoderContext, output)
         : flacDecodeToArray(nativeDecoderContext, output.array());
@@ -176,11 +176,14 @@ import java.nio.ByteBuffer;
 
   private native long flacInit();
 
-  private native FlacStreamInfo flacDecodeMetadata(long context);
+  private native FlacStreamInfo flacDecodeMetadata(long context)
+      throws IOException, InterruptedException;
 
-  private native int flacDecodeToBuffer(long context, ByteBuffer outputBuffer);
+  private native int flacDecodeToBuffer(long context, ByteBuffer outputBuffer)
+      throws IOException, InterruptedException;
 
-  private native int flacDecodeToArray(long context, byte[] outputArray);
+  private native int flacDecodeToArray(long context, byte[] outputArray)
+      throws IOException, InterruptedException;
 
   private native long flacGetLastTimestamp(long context);