Implement MediaSession on top of the WebMediaPlayerDelegate.

content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java

Index: content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java
diff --git a/content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java b/content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java
index f9c2801fa2430643768007542468eabfe43f0483..1f43af6d7547d26d104570d14b11e5da96e225fd 100644
--- a/content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java
+++ b/content/public/test/android/javatests/src/org/chromium/content/browser/test/util/DOMUtils.java
@@ -76,6 +76,17 @@ public class DOMUtils {
     }
 
     /**
+     * Returns the current time of the media with given {@code id}.
+     * @param webContents The WebContents in which the media element lives.
+     * @param id The element's id to check.
+     * @return the current time (in seconds) of the media.
+     */
+    private static double getCurrentTime(final WebContents webContents, final String id)
+            throws InterruptedException, TimeoutException {
+        return getNodeField("currentTime", webContents, id, Double.class);
+    }
+
+    /**
      * Waits until the playback of the media with given {@code id} has started.
      * @param webContents The WebContents in which the media element lives.
      * @param id The element's id to check.
@@ -86,7 +97,9 @@ public class DOMUtils {
             @Override
             public boolean isSatisfied() {
                 try {
-                    return !DOMUtils.isMediaPaused(webContents, id);
+                    // Playback can't be reliably detected until current time moves forward.
+                    return !DOMUtils.isMediaPaused(webContents, id)
+                            && DOMUtils.getCurrentTime(webContents, id) > 0;

[mlamouri (slow - plz ping), 2016/01/26 21:02:50]

I think the test fails because of this. We used to pass the test if play() was
successful. Did you try without this? or maybe with another file?

[DaleCurtis, 2016/01/26 21:23:33]

Haven't tried w/o this. It's possible this is changing the timing, but I think
it only let the existing test scrape by with success due to faster timing. The
test is failing because current time jumps from ~16ms to 2.1seconds instantly
for some reason. I'm sending runs to the bots with extra logging to track this
down.

[DaleCurtis, 2016/01/26 21:59:27]

Looks like MediaPlayerBridge is returning the duration as current time
milliseconds after playback starts....
ERROR:media_player_bridge.cc(519)] OnTimeUpdateTimerFired current_time: 2001000

I think 4.4.4 images may have problems playing these files... Rebuilding my
emulator with the same image the bots use.

[DaleCurtis, 2016/01/27 00:17:08]

I can't get the emulator up, so I'll have to image a device tomorrow with 4.4.4.
In the meantime I'm adding mp3 versions of the ogg clips. It's possible these
test clips have never played on the bots before, but due to timing the tests are
still passing.

[DaleCurtis, 2016/01/27 02:25:13]

Using mp3 clips causes the tests to pass, so I've added a secondary set of mp3
(but left the .ogg for when proprietary_codecs=false in the potential future). I
chose mp3 instead of mp4 since WMPA unfortunately does its detection based on
mime types.

[DaleCurtis, 2016/01/27 02:31:12]

I should mention I validated the ogg files with oggz-validate and they appear
correct, so I'm not sure why Android 4.4.4 (as used by the bots) can't play
these files. I'm unable to get an emulator image with this working locally,
though I will try to image a device tomorrow for further investigations.

                 } catch (InterruptedException e) {
                     // Intentionally do nothing
                     return false;