Fix onLoad* event media times for multi-period case

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=137932100

library/src/main/java/com/google/android/exoplayer2/source/AdaptiveMediaSourceEventListener.java

@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.source;
 
-import static com.google.android.exoplayer2.C.usToMs;
-
 import android.os.Handler;
 import android.os.SystemClock;
 import com.google.android.exoplayer2.C;
@@ -174,10 +172,21 @@ public interface AdaptiveMediaSourceEventListener {
 
     private final Handler handler;
     private final AdaptiveMediaSourceEventListener listener;
+    private final long mediaTimeOffsetMs;
 
     public EventDispatcher(Handler handler, AdaptiveMediaSourceEventListener listener) {
+      this(handler, listener, 0);
+    }
+
+    public EventDispatcher(Handler handler, AdaptiveMediaSourceEventListener listener,
+        long mediaTimeOffsetMs) {
       this.handler = listener != null ? Assertions.checkNotNull(handler) : null;
       this.listener = listener;
+      this.mediaTimeOffsetMs = mediaTimeOffsetMs;
+    }
+
+    public EventDispatcher copyWithMediaTimeOffsetMs(long mediaTimeOffsetMs) {
+      return new EventDispatcher(handler, listener, mediaTimeOffsetMs);
     }
 
     public void loadStarted(DataSpec dataSpec, int dataType, long elapsedRealtimeMs) {
@@ -193,8 +202,8 @@ public interface AdaptiveMediaSourceEventListener {
           @Override
           public void run() {
             listener.onLoadStarted(dataSpec, dataType, trackType, trackFormat, trackSelectionReason,
-                trackSelectionData, usToMs(mediaStartTimeUs), usToMs(mediaEndTimeUs),
-                elapsedRealtimeMs);
+                trackSelectionData, adjustMediaTime(mediaStartTimeUs),
+                adjustMediaTime(mediaEndTimeUs), elapsedRealtimeMs);
           }
         });
       }
@@ -215,8 +224,8 @@ public interface AdaptiveMediaSourceEventListener {
           @Override
           public void run() {
             listener.onLoadCompleted(dataSpec, dataType, trackType, trackFormat,
-                trackSelectionReason, trackSelectionData, usToMs(mediaStartTimeUs),
-                usToMs(mediaEndTimeUs), elapsedRealtimeMs, loadDurationMs, bytesLoaded);
+                trackSelectionReason, trackSelectionData, adjustMediaTime(mediaStartTimeUs),
+                adjustMediaTime(mediaEndTimeUs), elapsedRealtimeMs, loadDurationMs, bytesLoaded);
           }
         });
       }
@@ -237,8 +246,8 @@ public interface AdaptiveMediaSourceEventListener {
           @Override
           public void run() {
             listener.onLoadCanceled(dataSpec, dataType, trackType, trackFormat,
-                trackSelectionReason, trackSelectionData, usToMs(mediaStartTimeUs),
-                usToMs(mediaEndTimeUs), elapsedRealtimeMs, loadDurationMs, bytesLoaded);
+                trackSelectionReason, trackSelectionData, adjustMediaTime(mediaStartTimeUs),
+                adjustMediaTime(mediaEndTimeUs), elapsedRealtimeMs, loadDurationMs, bytesLoaded);
           }
         });
       }
@@ -261,8 +270,9 @@ public interface AdaptiveMediaSourceEventListener {
           @Override
           public void run() {
             listener.onLoadError(dataSpec, dataType, trackType, trackFormat, trackSelectionReason,
-                trackSelectionData, usToMs(mediaStartTimeUs), usToMs(mediaEndTimeUs),
-                elapsedRealtimeMs, loadDurationMs, bytesLoaded, error, wasCanceled);
+                trackSelectionData, adjustMediaTime(mediaStartTimeUs),
+                adjustMediaTime(mediaEndTimeUs), elapsedRealtimeMs, loadDurationMs, bytesLoaded,
+                error, wasCanceled);
           }
         });
       }
@@ -274,8 +284,8 @@ public interface AdaptiveMediaSourceEventListener {
         handler.post(new Runnable()  {
           @Override
           public void run() {
-            listener.onUpstreamDiscarded(trackType, usToMs(mediaStartTimeUs),
-                usToMs(mediaEndTimeUs));
+            listener.onUpstreamDiscarded(trackType, adjustMediaTime(mediaStartTimeUs),
+                adjustMediaTime(mediaEndTimeUs));
           }
         });
       }
@@ -289,12 +299,17 @@ public interface AdaptiveMediaSourceEventListener {
           @Override
           public void run() {
             listener.onDownstreamFormatChanged(trackType, trackFormat, trackSelectionReason,
-                trackSelectionData, usToMs(mediaTimeUs));
+                trackSelectionData, adjustMediaTime(mediaTimeUs));
           }
         });
       }
     }
 
+    private long adjustMediaTime(long mediaTimeUs) {
+      long mediaTimeMs = C.usToMs(mediaTimeUs);
+      return mediaTimeMs == C.TIME_UNSET ? C.TIME_UNSET : mediaTimeOffsetMs + mediaTimeMs;
+    }
+
   }
 
 }

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

@@ -170,10 +170,12 @@ public final class DashMediaSource implements MediaSource {
   }
 
   @Override
-  public MediaPeriod createPeriod(int index, Allocator allocator, long positionUs) {
-    DashMediaPeriod mediaPeriod = new DashMediaPeriod(firstPeriodId + index, manifest, index,
-        chunkSourceFactory, minLoadableRetryCount, eventDispatcher, elapsedRealtimeOffsetMs, loader,
-        allocator);
+  public MediaPeriod createPeriod(int periodIndex, Allocator allocator, long positionUs) {
+    EventDispatcher periodEventDispatcher = eventDispatcher.copyWithMediaTimeOffsetMs(
+        manifest.getPeriod(periodIndex).startMs);
+    DashMediaPeriod mediaPeriod = new DashMediaPeriod(firstPeriodId + periodIndex, manifest,
+        periodIndex, chunkSourceFactory, minLoadableRetryCount, periodEventDispatcher,
+        elapsedRealtimeOffsetMs, loader, allocator);
     periodsById.put(mediaPeriod.id, mediaPeriod);
     return mediaPeriod;
   }

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

@@ -41,12 +41,12 @@ public class Period {
 
   /**
    * @param id The period identifier. May be null.
-   * @param start The start time of the period in milliseconds.
+   * @param startMs The start time of the period in milliseconds.
    * @param adaptationSets The adaptation sets belonging to the period.
    */
-  public Period(String id, long start, List<AdaptationSet> adaptationSets) {
+  public Period(String id, long startMs, List<AdaptationSet> adaptationSets) {
     this.id = id;
-    this.startMs = start;
+    this.startMs = startMs;
     this.adaptationSets = Collections.unmodifiableList(adaptationSets);
   }