[PPAPI][MediaStream] Support configure for video input.

ppapi/examples/media_stream_video/media_stream_video.html

Index: ppapi/examples/media_stream_video/media_stream_video.html
diff --git a/ppapi/examples/media_stream_video/media_stream_video.html b/ppapi/examples/media_stream_video/media_stream_video.html
index a20c284cc25572453902e32bd24b4121b05b16b0..8e83de367301584c40721bea3743fafa8c15f059 100644
--- a/ppapi/examples/media_stream_video/media_stream_video.html
+++ b/ppapi/examples/media_stream_video/media_stream_video.html
@@ -17,7 +17,7 @@
 
     function success(s) {
       stream = s;
-      plugin.postMessage({track: stream.getVideoTracks()[0]});
+      plugin.postMessage({command: 'init', track: stream.getVideoTracks()[0]});
     }
 
     function failure(e) {
@@ -31,8 +31,8 @@
         "audio": false,
         "video": {
           "mandatory": {
-            "minWidth": "1280",
-            "minHeight": "720",
+            "minWidth": "640",
+            "minHeight": "320",
             "minFrameRate": "30"
           },
           "optional": []
@@ -41,6 +41,13 @@
       navigator.webkitGetUserMedia(constraints, success, failure);
     }
 
+    function changeFormat(format) {
+      plugin.postMessage({command:'format', format: format});
+    }
+
+    function changeSize(width, height) {
+      plugin.postMessage({command:'size', width: width, height: height});
+    }
     document.addEventListener('DOMContentLoaded', initialize, false);
   </script>
 </head>
@@ -50,6 +57,16 @@
   This example demonstrates receiving frames from a video MediaStreamTrack and
   rendering them in a plugin.<br>
   <embed id="plugin" type="application/x-ppapi-example-media-stream-video"
-      width="320" height="240"/>
+  width="640" height="240"/>
+  <h2>Format:</h2><br>
+  <button onclick="changeFormat('YV12')" >YV12</button>
+  <button onclick="changeFormat('I420')" >I420</button>
+  <button onclick="changeFormat('BGRA')" >BGRA</button>
+  <button onclick="changeFormat('DEFAULT')" >DEFAULT</button>
+  <h2>Size:</h2><br>
+  <button onclick="changeSize(72, 72)" >72 x 72</button>
+  <button onclick="changeSize(640, 360)" >640 x 360</button>
+  <button onclick="changeSize(1280, 720)" >1280 x 720</button>
+  <button onclick="changeSize(0, 0)" >DEFAULT</button>
 </body>
 </html>