Add HD browser test to WebRTC suite.

chrome/test/data/webrtc/video_detector.js

Index: chrome/test/data/webrtc/video_detector.js
diff --git a/chrome/test/data/webrtc/video_detector.js b/chrome/test/data/webrtc/video_detector.js
index 3c10813aad7058ffe8c58033ad60a0599821c495..0087298df31026ef02e5c08fae82cfc4e6fd3ced 100644
--- a/chrome/test/data/webrtc/video_detector.js
+++ b/chrome/test/data/webrtc/video_detector.js
@@ -48,6 +48,30 @@ function startDetection(videoElementId, width, height) {
 }
 
 /**
+ * Verifies that the video stream connected to a video tag has the right width
+ * and height.
+ *
+ * @param {string} videoElementId The video element to analyze.
+ * @param {int}    width The expected video width.
+ * @param {int}    width The expected video height.
+ *
+ * @return {string} Returns 'ok' if passing (exception is thrown on failure).
+ */
+function verifyVideoStreamSize(videoElementId, expectedWidth, expectedHeight) {
+  var videoTag = document.getElementById(videoElementId);
+  console.log('videoTag' + videoTag);
+  if (videoTag.videoWidth == expectedWidth &&
+      videoTag.videoHeight == expectedHeight) {
+    returnToTest('ok-video-stream-size');
+  }
+  else {
+    throw failTest('Invalid video stream size: ' + videoTag.videoWidth +
+        'x' + videoTag.videoHeight + ' (expected: ' + expectedWidth + 'x' +
+        expectedHeight + ')');
+  }
+}
+
+/**
  * Checks if we have detected any video so far.
  *
  * @return {string} video-playing if we detected video, otherwise