Fix some typos/consistency nits.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132876946

demo/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java

@@ -353,10 +353,11 @@ public class PlayerActivity extends Activity implements OnClickListener, ExoPlay
   }
 
   /**
-   * Build a DataSource factory.
+   * Returns a new DataSource factory.
    *
    * @param useBandwidthMeter Whether to set {@link #BANDWIDTH_METER} as a listener to the new
    *     DataSource factory.
+   * @return A new DataSource factory.
    */
   private DataSource.Factory buildDataSourceFactory(boolean useBandwidthMeter) {
     return new DefaultDataSourceFactory(this, useBandwidthMeter ? BANDWIDTH_METER : null,
@@ -364,10 +365,11 @@ public class PlayerActivity extends Activity implements OnClickListener, ExoPlay
   }
 
   /**
-   * Build a HttpDataSource factory.
+   * Returns a new HttpDataSource factory.
    *
    * @param useBandwidthMeter Whether to set {@link #BANDWIDTH_METER} as a listener to the new
    *     DataSource factory.
+   * @return A new HttpDataSource factory.
    */
   private HttpDataSource.Factory buildHttpDataSourceFactory(boolean useBandwidthMeter) {
     return new DefaultHttpDataSourceFactory(userAgent, useBandwidthMeter ? BANDWIDTH_METER : null);

library/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -52,7 +52,7 @@ package com.google.android.exoplayer2;
  *   <img src="doc-files/timeline-live-limited.svg" alt="Example timeline for a live stream with
  *       limited availability">
  * </p>
- * A timeline for a live stream consists of a period whose duration is unknown, since its
+ * A timeline for a live stream consists of a period whose duration is unknown, since it's
  * continually extending as more content is broadcast. If content only remains available for a
  * limited period of time then the window may start at a non-zero position, defining the region of
  * content that can still be played. The window will have {@link Window#isDynamic} set to true if

library/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecUtil.java

@@ -319,7 +319,7 @@ public final class MediaCodecUtil {
     switch (parts[0]) {
       case CODEC_ID_HEV1:
       case CODEC_ID_HVC1:
-        return getHevcProileAndLevel(codec, parts);
+        return getHevcProfileAndLevel(codec, parts);
       case CODEC_ID_AVC1:
       case CODEC_ID_AVC2:
         return getAvcProfileAndLevel(codec, parts);
@@ -328,7 +328,7 @@ public final class MediaCodecUtil {
     }
   }
 
-  private static Pair<Integer, Integer> getHevcProileAndLevel(String codec, String[] parts) {
+  private static Pair<Integer, Integer> getHevcProfileAndLevel(String codec, String[] parts) {
     if (parts.length < 4) {
       // The codec has fewer parts than required by the HEVC codec string format.
       Log.w(TAG, "Ignoring malformed HEVC codec string: " + codec);

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

@@ -96,7 +96,6 @@ import java.util.Locale;
    * gaps in playback in case playlist drift apart.
    */
   private static final double LIVE_VARIANT_SWITCH_SAFETY_EXTRA_SECS = 2.0;
-  private static final String TAG = "HlsChunkSource";
   private static final String AAC_FILE_EXTENSION = ".aac";
   private static final String AC3_FILE_EXTENSION = ".ac3";
   private static final String EC3_FILE_EXTENSION = ".ec3";
@@ -242,7 +241,7 @@ import java.util.Locale;
     int chunkMediaSequence;
     if (live) {
       if (previous == null) {
-        // When playling a live stream, the starting chunk will be the third counting from the live
+        // When playing a live stream, the starting chunk will be the third counting from the live
         // edge.
         chunkMediaSequence = Math.max(0, mediaPlaylist.segments.size() - 3)
             + mediaPlaylist.mediaSequence;

library/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -929,8 +929,7 @@ public final class Util {
       if ("Sony".equals(Util.MANUFACTURER) && Util.MODEL.startsWith("BRAVIA")
           && context.getPackageManager().hasSystemFeature("com.sony.dtv.hardware.panel.qfhd")) {
         return new Point(3840, 2160);
-      } else if ("NVIDIA".equals(Util.MANUFACTURER) && Util.MODEL != null
+      } else if ("NVIDIA".equals(Util.MANUFACTURER) && Util.MODEL.contains("SHIELD")) {
-          && Util.MODEL.contains("SHIELD")) {
         // Attempt to read sys.display-size.
         String sysDisplaySize = null;
         try {