Make ExoPlayer systrace consistent.

Plus remove some unused util methods + make a few
warnings go away.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123888046

extensions/vp9/src/main/java/com/google/android/exoplayer/ext/vp9/LibvpxVideoTrackRenderer.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer.TrackStream;
 import com.google.android.exoplayer.VideoTrackRendererEventListener;
 import com.google.android.exoplayer.VideoTrackRendererEventListener.EventDispatcher;
 import com.google.android.exoplayer.util.MimeTypes;
+import com.google.android.exoplayer.util.TraceUtil;
 
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
@@ -152,15 +153,19 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
       if (decoder == null) {
         // If we don't have a decoder yet, we need to instantiate one.
         long codecInitializingTimestamp = SystemClock.elapsedRealtime();
+        TraceUtil.beginSection("createVpxDecoder");
         decoder = new VpxDecoder(NUM_BUFFERS, NUM_BUFFERS, INITIAL_INPUT_BUFFER_SIZE);
         decoder.setOutputMode(outputMode);
+        TraceUtil.endSection();
         long codecInitializedTimestamp = SystemClock.elapsedRealtime();
         eventDispatcher.decoderInitialized(decoder.getName(), codecInitializedTimestamp,
             codecInitializedTimestamp - codecInitializingTimestamp);
         codecCounters.codecInitCount++;
       }
+      TraceUtil.beginSection("drainAndFeed");
       while (drainOutputBuffer(positionUs)) {}
       while (feedInputBuffer()) {}
+      TraceUtil.endSection();
     } catch (VpxDecoderException e) {
       throw ExoPlaybackException.createForRenderer(e, getIndex());
     }

library/src/main/java/com/google/android/exoplayer/MediaCodecTrackRenderer.java

@@ -306,13 +306,13 @@ public abstract class MediaCodecTrackRenderer extends TrackRenderer {
     codecNeedsMonoChannelCountWorkaround = codecNeedsMonoChannelCountWorkaround(codecName, format);
     try {
       long codecInitializingTimestamp = SystemClock.elapsedRealtime();
-      TraceUtil.beginSection("createByCodecName(" + codecName + ")");
+      TraceUtil.beginSection("createCodec:" + codecName);
       codec = MediaCodec.createByCodecName(codecName);
       TraceUtil.endSection();
       TraceUtil.beginSection("configureCodec");
       configureCodec(codec, format, mediaCrypto);
       TraceUtil.endSection();
-      TraceUtil.beginSection("codec.start()");
+      TraceUtil.beginSection("startCodec");
       codec.start();
       TraceUtil.endSection();
       long codecInitializedTimestamp = SystemClock.elapsedRealtime();

library/src/main/java/com/google/android/exoplayer/extensions/AudioDecoderTrackRenderer.java

@@ -28,6 +28,7 @@ import com.google.android.exoplayer.TrackRenderer;
 import com.google.android.exoplayer.TrackStream;
 import com.google.android.exoplayer.audio.AudioTrack;
 import com.google.android.exoplayer.util.MimeTypes;
+import com.google.android.exoplayer.util.TraceUtil;
 
 import android.media.PlaybackParams;
 import android.os.Handler;
@@ -98,7 +99,9 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     if (decoder == null) {
       try {
         long codecInitializingTimestamp = SystemClock.elapsedRealtime();
+        TraceUtil.beginSection("createAudioDecoder");
         decoder = createDecoder(inputFormat);
+        TraceUtil.endSection();
         long codecInitializedTimestamp = SystemClock.elapsedRealtime();
         eventDispatcher.decoderInitialized(decoder.getName(), codecInitializedTimestamp,
             codecInitializedTimestamp - codecInitializingTimestamp);
@@ -110,8 +113,10 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
 
     // Rendering loop.
     try {
+      TraceUtil.beginSection("drainAndFeed");
       while (drainOutputBuffer()) {}
       while (feedInputBuffer()) {}
+      TraceUtil.endSection();
     } catch (AudioTrack.InitializationException | AudioTrack.WriteException
         | AudioDecoderException e) {
       throw ExoPlaybackException.createForRenderer(e, getIndex());

library/src/main/java/com/google/android/exoplayer/upstream/Loader.java

@@ -251,7 +251,7 @@ public final class Loader {
       try {
         executorThread = Thread.currentThread();
         if (!loadable.isLoadCanceled()) {
-          TraceUtil.beginSection(loadable.getClass().getSimpleName() + ".load()");
+          TraceUtil.beginSection("load:" + loadable.getClass().getSimpleName());
           try {
             loadable.load();
           } finally {

library/src/main/java/com/google/android/exoplayer/util/UriUtil.java

@@ -116,7 +116,7 @@ public final class UriUtil {
       return removeDotSegments(uri, baseLimit + refIndices[PATH], baseLimit + refIndices[QUERY]);
     }
 
-    if (refIndices[PATH] != refIndices[QUERY] && referenceUri.charAt(refIndices[PATH]) == '/') {
+    if (referenceUri.charAt(refIndices[PATH]) == '/') {
       // The reference path is rooted. The target is the base scheme and authority (if any), plus
       // the reference.
       uri.append(baseUri, 0, baseIndices[PATH]).append(referenceUri);

library/src/main/java/com/google/android/exoplayer/util/Util.java

@@ -20,10 +20,8 @@ import com.google.android.exoplayer.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.upstream.DataSpec;
 
-import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.pm.PackageInfo;
-import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.net.Uri;
 import android.os.Build;
@@ -46,7 +44,6 @@ import java.util.Locale;
 import java.util.TimeZone;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ThreadFactory;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -118,17 +115,6 @@ public final class Util {
 
   private Util() {}
 
-  /**
-   * Returns whether the device is an AndroidTV.
-   *
-   * @param context A context.
-   * @return True if the device is an AndroidTV. False otherwise.
-   */
-  @SuppressLint("InlinedApi")
-  public static boolean isAndroidTv(Context context) {
-    return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_LEANBACK);
-  }
-
   /**
    * Converts microseconds to milliseconds (rounding down).
    *
@@ -213,21 +199,6 @@ public final class Util {
     });
   }
 
-  /**
-   * Instantiates a new single threaded scheduled executor whose thread has the specified name.
-   *
-   * @param threadName The name of the thread.
-   * @return The executor.
-   */
-  public static ScheduledExecutorService newSingleThreadScheduledExecutor(final String threadName) {
-    return Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
-      @Override
-      public Thread newThread(Runnable r) {
-        return new Thread(r, threadName);
-      }
-    });
-  }
-
   /**
    * Closes a {@link DataSource}, suppressing any {@link IOException} that may occur.
    *
@@ -598,10 +569,10 @@ public final class Util {
         unexpectedEndOfInput.setAccessible(true);
         unexpectedEndOfInput.invoke(inputStream);
       }
-    } catch (IOException e) {
-      // The connection didn't ever have an input stream, or it was closed already.
     } catch (Exception e) {
-      // Something went wrong. The device probably isn't using okhttp.
+      // If an IOException then the connection didn't ever have an input stream, or it was closed
+      // already. If another type of exception then something went wrong, most likely the device
+      // isn't using okhttp.
     }
   }
 
@@ -660,22 +631,6 @@ public final class Util {
     return ((long) topInteger << 32) | (bottomInteger & 0xFFFFFFFFL);
   }
 
-  /**
-   * Returns a hex string representation of the data provided.
-   *
-   * @param data The byte array containing the data to be turned into a hex string.
-   * @param beginIndex The begin index, inclusive.
-   * @param endIndex The end index, exclusive.
-   * @return A string containing the hex representation of the data provided.
-   */
-  public static String getHexStringFromBytes(byte[] data, int beginIndex, int endIndex) {
-    StringBuilder dataStringBuilder = new StringBuilder(endIndex - beginIndex);
-    for (int i = beginIndex; i < endIndex; i++) {
-      dataStringBuilder.append(String.format(Locale.US, "%02X", data[i]));
-    }
-    return dataStringBuilder.toString();
-  }
-
   /**
    * Returns a byte array containing values parsed from the hex string provided.
    *