Check context is attached before creating MediaRecorder

Bug: 896736 Change-Id: I3ccfd2188fb15704af14c8af050e0a5667855d34 Reviewed-on: https://chromium-review.googlesource.com/c/1324231 Commit-Queue: Emircan Uysaler <emircan@chromium.org> Reviewed-by: Miguel Casas <mcasas@chromium.org> Cr-Commit-Position: refs/heads/master@{#606242}

Check context is attached before creating MediaRecorder
Bug: 896736 Change-Id: I3ccfd2188fb15704af14c8af050e0a5667855d34 Reviewed-on: https://chromium-review.googlesource.com/c/1324231 Commit-Queue: Emircan Uysaler <emircan@chromium.org> Reviewed-by: Miguel Casas <mcasas@chromium.org> Cr-Commit-Position: refs/heads/master@{#606242}
f5ef337d · Emircan Uysaler · Commit Bot · 7969de66 · f5ef337d · f5ef337d
Commit f5ef337d authored Nov 08, 2018 by Emircan Uysaler Committed by Commit Bot Nov 08, 2018
3 changed files
--- a/content/renderer/media_recorder/media_recorder_handler.cc
+++ b/content/renderer/media_recorder/media_recorder_handler.cc
@@ -133,10 +133,11 @@ MediaRecorderHandler::MediaRecorderHandler(
 MediaRecorderHandler::~MediaRecorderHandler() {
  DCHECK(main_render_thread_checker_.CalledOnValidThread());
  // Send a |last_in_slice| to our |client_|.
-  if (client_)
+  if (client_) {
    client_->WriteData(
        nullptr, 0u, true,
        (TimeTicks::Now() - TimeTicks::UnixEpoch()).InMillisecondsF());
+  }
 }
 bool MediaRecorderHandler::CanSupportMimeType(

--- a/third_party/WebKit/LayoutTests/fast/mediarecorder/MediaRecorder-detached-context.html
+++ b/third_party/WebKit/LayoutTests/fast/mediarecorder/MediaRecorder-detached-context.html
+<!DOCTYPE html>
+<script src=../../resources/testharness.js></script>
+<script src=../../resources/testharnessreport.js></script>
+<body>
+<script>
+promise_test(async t => {
+  const frame = document.body.appendChild(document.createElement('iframe'));
+  const recorderFunc = frame.contentWindow.MediaRecorder;
+  frame.remove();
+  try {
+    new recorderFunc(new MediaStream);
+  } catch (err) {
+    assert_equals(err.name, 'NotAllowedError');
+    return;
+  }
+  assert_unreached('MediaRecorder should have failed');
+}, 'MediaRecorder creation with detached context');
+</script>
+</body>
--- a/third_party/blink/renderer/modules/mediarecorder/media_recorder.cc
+++ b/third_party/blink/renderer/modules/mediarecorder/media_recorder.cc
@@ -175,8 +175,13 @@ MediaRecorder::MediaRecorder(ExecutionContext* context,
          this,
          &MediaRecorder::DispatchScheduledEvent,
          context->GetTaskRunner(TaskType::kDOMManipulation))) {
-  DCHECK(stream_->getTracks().size());
+  if (context->IsContextDestroyed()) {
+    exception_state.ThrowDOMException(DOMExceptionCode::kNotAllowedError,
+                                      "Execution context is detached.");
+    return;
+  }
+  DCHECK(stream_->getTracks().size());
  recorder_handler_ = Platform::Current()->CreateMediaRecorderHandler(
      context->GetTaskRunner(TaskType::kInternalMediaRealTime));
  DCHECK(recorder_handler_);