webcodecs: Updating VPX and MF encoders to heed the VBR setting

Bug: 1217840
Change-Id: I9067e6a690f1f9634d1bcf3f6d5c7e0a469cff27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2946127
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Eugene Zemtsov <eugene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#901884}
diff --git a/webcodecs/videoFrame-createImageBitmap.any.js b/webcodecs/videoFrame-createImageBitmap.any.js
index 7b08d29..415d0bb 100644
--- a/webcodecs/videoFrame-createImageBitmap.any.js
+++ b/webcodecs/videoFrame-createImageBitmap.any.js
@@ -83,7 +83,7 @@
           let myCanvas = new OffscreenCanvas(width, height);
           let myCtx = myCanvas.getContext('2d');
           myCtx.drawImage(toImageBitmap, 0, 0);
-          let tolerance = 6;
+          let tolerance = 10;
           try {
             testCanvas(myCtx, width, height, kSRGBPixel, null,
               (actual, expected) => {
@@ -128,7 +128,7 @@
         width: width,
         height: height,
         bitrate: 10e6,
-        framerate: 30,
+        framerate: 30
       };
 
       let encoder = new VideoEncoder(encoderInit);