Update basic_media_playback tests to use media files in content/test/data

chrome/test/data/media files that were copied in r148190 in preparation for r148349

BUG=125424
NOTRY=true
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10825038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148756 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/media/html/media_basic_playback.html

@@ -52,7 +52,7 @@
 
     function startTest(media) {
       events = [];
-      video.src = '../' + media;
+      video.src = media;
     }
   </script>
 </html>

chrome/test/functional/media/media_basic_playback.py

@@ -22,8 +22,9 @@ _TEST_HTML_PATH = os.path.join('media', 'html', 'media_basic_playback.html')
 # have more test videos in the matrix.  Code already written, see patch here:
 # https://chromiumcodereview.appspot.com/9290008/#ps12
 _TEST_VIDEOS = [
-    'bear.mp4', 'bear.ogv', 'bear.webm', 'bear_silent.mp4', 'bear_silent.ogv',
-    'bear_silent.webm']
+    os.path.join(pyauto.PyUITest.ContentDataDir(), 'media', name)
+    for name in ['bear.mp4', 'bear.ogv', 'bear.webm', 'bear_silent.mp4',
+                 'bear_silent.ogv', 'bear_silent.webm']]
 
 # Expected events for the first iteration and every iteration thereafter.
 _EXPECTED_EVENTS_0 = [('ended', 2), ('playing', 2), ('seeked', 1)]