Add a custom time bar view.

Also add an isAd flag to Timeline.Period so that periods can be declared as
containing ads. The times of these periods are indicated using ad markers in
the new TimeBar.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=151116208

library/core/src/androidTest/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -334,7 +334,7 @@ public int getPeriodCount() {
     public Period getPeriod(int periodIndex, Period period, boolean setIds) {
       TimelineWindowDefinition windowDefinition = windowDefinitions[periodIndex];
       Object id = setIds ? periodIndex : null;
-      return period.set(id, id, periodIndex, windowDefinition.durationUs, 0);
+      return period.set(id, id, periodIndex, windowDefinition.durationUs, 0, false);
     }
 
     @Override

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

@@ -383,18 +383,24 @@ public static final class Period {
      */
     public long durationUs;
 
+    /**
+     * Whether this period contains an ad.
+     */
+    public boolean isAd;
+
     private long positionInWindowUs;
 
     /**
      * Sets the data held by this period.
      */
     public Period set(Object id, Object uid, int windowIndex, long durationUs,
-        long positionInWindowUs) {
+        long positionInWindowUs, boolean isAd) {
       this.id = id;
       this.uid = uid;
       this.windowIndex = windowIndex;
       this.durationUs = durationUs;
       this.positionInWindowUs = positionInWindowUs;
+      this.isAd = isAd;
       return this;
     }
 

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

@@ -158,6 +158,7 @@ public int getIndexOfPeriod(Object uid) {
       int periodIndexOffset = loopCount * childPeriodCount;
       return childTimeline.getIndexOfPeriod(loopCountAndChildUid.second) + periodIndexOffset;
     }
+
   }
 
 }

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

@@ -99,7 +99,7 @@ public int getPeriodCount() {
   public Period getPeriod(int periodIndex, Period period, boolean setIds) {
     Assertions.checkIndex(periodIndex, 0, 1);
     Object id = setIds ? ID : null;
-    return period.set(id, id, 0, periodDurationUs, -windowPositionInPeriodUs);
+    return period.set(id, id, 0, periodDurationUs, -windowPositionInPeriodUs, false);
   }
 
   @Override

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

@@ -45,6 +45,7 @@
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Collections;
+import java.util.Formatter;
 import java.util.GregorianCalendar;
 import java.util.List;
 import java.util.Locale;
@@ -309,6 +310,18 @@ public static int constrainValue(int value, int min, int max) {
     return Math.max(min, Math.min(value, max));
   }
 
+  /**
+   * Constrains a value to the specified bounds.
+   *
+   * @param value The value to constrain.
+   * @param min The lower bound.
+   * @param max The upper bound.
+   * @return The constrained value {@code Math.max(min, Math.min(value, max))}.
+   */
+  public static long constrainValue(long value, long min, long max) {
+    return Math.max(min, Math.min(value, max));
+  }
+
   /**
    * Constrains a value to the specified bounds.
    *
@@ -835,6 +848,27 @@ public static int inferContentType(String fileName) {
     }
   }
 
+  /**
+   * Returns the specified millisecond time formatted as a string.
+   *
+   * @param builder The builder that {@code formatter} will write to.
+   * @param formatter The formatter.
+   * @param timeMs The time to format as a string, in milliseconds.
+   * @return The time formatted as a string.
+   */
+  public static String getStringForTime(StringBuilder builder, Formatter formatter, long timeMs) {
+    if (timeMs == C.TIME_UNSET) {
+      timeMs = 0;
+    }
+    long totalSeconds = (timeMs + 500) / 1000;
+    long seconds = totalSeconds % 60;
+    long minutes = (totalSeconds / 60) % 60;
+    long hours = totalSeconds / 3600;
+    builder.setLength(0);
+    return hours > 0 ? formatter.format("%d:%02d:%02d", hours, minutes, seconds).toString()
+        : formatter.format("%02d:%02d", minutes, seconds).toString();
+  }
+
   /**
    * Maps a {@link C} {@code TRACK_TYPE_*} constant to the corresponding {@link C}
    * {@code DEFAULT_*_BUFFER_SIZE} constant.

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java

@@ -648,7 +648,7 @@ public Period getPeriod(int periodIndex, Period period, boolean setIdentifiers)
           + Assertions.checkIndex(periodIndex, 0, manifest.getPeriodCount()) : null;
       return period.set(id, uid, 0, manifest.getPeriodDurationUs(periodIndex),
           C.msToUs(manifest.getPeriod(periodIndex).startMs - manifest.getPeriod(0).startMs)
-              - offsetInFirstPeriodUs);
+              - offsetInFirstPeriodUs, false);
     }
 
     @Override