Merge pull request #13824 from huchengtw-moz/video/Bug_938967_00-00_i…

…s_not_handle_correctly

Bug 938967 - [fugu][hamachi]The video had be sought to 00:00 could not b..., r=djf

apps/video/js/video.js

@@ -75,7 +75,7 @@ var pendingPick;
 // But Camera and Gallery also need to use that hardware, and those three apps
 // may only have one video playing at a time among them. So we need to be
 // careful to relinquish the hardware when we are not visible.
-var restoreTime;
+var restoreTime = null;
 
 // Videos recorded by our own camera have filenames of this form
 var FROMCAMERA = /DCIM\/\d{3}MZLLA\/VID_\d{4}\.3gp$/;
@@ -982,12 +982,22 @@ function releaseVideo() {
 
 // Call this when the app becomes visible again
 function restoreVideo() {
-  if (!restoreTime) {
-    return;
-  }
+  // When restoreVideo is called, we assume we have currentVideo because the
+  // playerShowing is true.
   setVideoUrl(dom.player, currentVideo, function() {
     setPlayerSize();
-    dom.player.currentTime = restoreTime;
+    // Everything is ready, start to restore last playing time.
+    if (restoreTime !== null) {
+      // restore to the last time when we have a valid restoreTime.
+      dom.player.currentTime = restoreTime;
+    } else {
+      // When we don't have valid restoreTime, we need to restore to the last
+      // viewing position from metadata. When user taps on a unwatched video and
+      // presses home quickly, the dom.player may not finish the loading of
+      // video and the restoreTime is null. At the same case, the currentTime of
+      // metadata is still undefined because we haven't updateMetadata.
+      dom.player.currentTime = currentVideo.metadata.currentTime || 0;
+    }
   });
 }