Speeding up TwoGetUserMediaAndStop WebRTC test

content/test/data/media/getusermedia.html

Index: content/test/data/media/getusermedia.html
diff --git a/content/test/data/media/getusermedia.html b/content/test/data/media/getusermedia.html
index f42ce720fd43c84433d85478fd675b7c56903838..280571e021657472f8f7e10bc98bd7f3aa8dcb62 100644
--- a/content/test/data/media/getusermedia.html
+++ b/content/test/data/media/getusermedia.html
@@ -163,37 +163,32 @@
 
   // Creates two MediaStream and renders them locally. When the video of both
   // streams are detected to be rolling, we stop the local video tracks one at
-  // the time.
+  // the time. In particular, we verify that stopping one track does not stop
+  // the other.
   function twoGetUserMediaAndStop(constraints) {
-    // TODO(phoglund): make gUM requests in parallel; this test is too slow
-    // and flakes on slow bots (http://crbug.com/417756). The current cycle of
-    // detect - gum - detect - gum - stop - detect - stop - detect contains too
-    // many detection phases. On bots with GPU emulation this looks to be really
-    // slow, so I was thinking we could at least get video up for both streams
-    // simultaneously and thereby run the first two detects in parallel.
     var stream1 = null;

[phoglund_chromium, 2014/10/09 12:20:07]

Unless of course you see a problem with doing the first gUMs in parallel
(although then I think our only option is to delete the test).

     var stream2 = null;
     navigator.webkitGetUserMedia(
         constraints,
         function(stream) {
           stream1 = stream;
-          detectVideoInLocalView1(stream, requestSecondGetUserMedia);
+          detectVideoInLocalView1(stream, maybeStopBothVideoTracksAndVerify);
+        },
+        failedCallback);
+    navigator.webkitGetUserMedia(
+        constraints,
+        function(stream) {
+          stream2 = stream;
+          attachMediaStream(stream, 'local-view-2');
+          detectVideoPlaying('local-view-2', maybeStopBothVideoTracksAndVerify);
         },
         failedCallback);
-    var requestSecondGetUserMedia = function() {
-      navigator.webkitGetUserMedia(
-          constraints,
-          function(stream) {
-            stream2 = stream;
-            attachMediaStream(stream, 'local-view-2');
-            detectVideoPlaying('local-view-2', stopBothVideoTracksAndVerify);
-          },
-          failedCallback);
-    };
 
-    var stopBothVideoTracksAndVerify = function() {
-      // Stop track 2, ensure that stops track 2 but not track 1, then stop
-      // track 1.
+    var maybeStopBothVideoTracksAndVerify = function() {
+      if (stream1 == null || stream2 == null)
+        return;
+
+      // Stop track 2, ensure track 2 stops but not track 1, then stop track 1.
       stream2.getVideoTracks()[0].stop();
       waitForVideoToStop('local-view-1');
       waitForVideoToStop('local-view-2');
@@ -203,35 +198,41 @@
     };
   }
 
-  function twoGetUserMedia(constraints1,
-                           constraints2) {
-    // TODO(phoglund): see TODO on twoGetUserMediaAndStop.
-    var result="";
+  // Makes to getUserMedia calls in parallel and detects the aspect ratio for
+  // both. The two aspect ratios are returned to the test separated by a dash,
+  // like for instance w=640:h=480-w=640:h=480.
+  function twoGetUserMedia(constraints1, constraints2) {
+    var aspectRatio1 = null;
+    var aspectRatio2 = null;
     navigator.webkitGetUserMedia(
         constraints1,
         function(stream) {
           displayDetectAndAnalyzeVideoInElement(
               stream,
               function(aspectRatio) {
-                result = aspectRatio;
-                requestSecondGetUserMedia();
+                aspectRatio1 = aspectRatio;
+                maybeFinishTest();
                },
               'local-view-1');
         },
         failedCallback);
-    var requestSecondGetUserMedia = function() {
-      navigator.webkitGetUserMedia(
-          constraints2,
-          function(stream) {
-            displayDetectAndAnalyzeVideoInElement(
-                stream,
-                function(aspectRatio) {
-                  result = result + '-' + aspectRatio;
-                  sendValueToTest(result);
-                },
-                'local-view-2');
-          },
-          failedCallback);
+    navigator.webkitGetUserMedia(
+        constraints2,
+        function(stream) {
+          displayDetectAndAnalyzeVideoInElement(
+              stream,
+              function(aspectRatio) {
+                aspectRatio2 = aspectRatio;
+                maybeFinishTest();
+              },
+              'local-view-2');
+        },
+        failedCallback);
+
+    var maybeFinishTest = function() {
+      if (aspectRatio1 == null || aspectRatio2 == null)
+        return;
+      sendValueToTest(aspectRatio1 + '-' + aspectRatio2);
     }
   }
 
@@ -241,19 +242,17 @@
                                              constraints2,
                                              expected_frame_rate1,
                                              expected_frame_rate2) {
-    // TODO(phoglund): see TODO on twoGetUserMediaAndStop.
     addExpectedEvent();
     addExpectedEvent();
-    var validateFrameRateCallback = function (success) {
-      if (!success)
-        failTest("Failed to validate frameRate.");
+    var validateFrameRateCallback = function (result) {
+      if (result != 'OK')
+        failTest(result);

[phoglund_chromium, 2014/10/09 12:20:07]

I've been annoyed by this rather bare error message, so I took the opportunity
to improve it.

       eventOccured();
     };
 
     navigator.webkitGetUserMedia(
         constraints1,
         function(stream) {
-          requestSecondGetUserMedia();
           attachMediaStream(stream, 'local-view-1');
           detectVideoPlaying('local-view-1',
               function() {
@@ -262,19 +261,17 @@
               });
         },
         failedCallback);
-    var requestSecondGetUserMedia = function() {
-      navigator.webkitGetUserMedia(
-          constraints2,
-          function(stream) {
-            attachMediaStream(stream, 'local-view-2');
-            detectVideoPlaying('local-view-2',
-                function() {
-                  validateFrameRate('local-view-2', expected_frame_rate2,
-                      validateFrameRateCallback);
-                });
-          },
-          failedCallback);
-    }
+    navigator.webkitGetUserMedia(
+        constraints2,
+        function(stream) {
+          attachMediaStream(stream, 'local-view-2');
+          detectVideoPlaying('local-view-2',
+              function() {
+                validateFrameRate('local-view-2', expected_frame_rate2,
+                    validateFrameRateCallback);
+              });
+        },
+        failedCallback);
   }
 
   function failedCallback(error) {