Adding an experimental flag to block autoplay with sound in cross-origin iframes

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index a1f0ce6a74d593703d34135af4a59c9ecdc1652e..d9c1fa87fdb721cdc9931c54bc9d23704c609200 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -285,6 +285,11 @@ String preloadTypeToString(WebMediaPlayer::Preload preloadType) {
   return String();
 }
 
+bool isDocumentCrossOrigin(Document& document) {
+  const LocalFrame* frame = document.frame();
+  return frame && frame->isCrossOriginSubframe();
+}
+
 }  // anonymous namespace
 
 class HTMLMediaElement::AutoplayHelperClientImpl
@@ -330,8 +335,7 @@ class HTMLMediaElement::AutoplayHelperClientImpl
 
   // Frame
   bool isCrossOrigin() const override {
-    const LocalFrame* frame = m_element->document().frame();
-    return frame && frame->isCrossOriginSubframe();
+    return isDocumentCrossOrigin(m_element->document());
   }
 
   bool isAutoplayAllowedPerSettings() const override;
@@ -469,13 +473,7 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName,
 
   BLINK_MEDIA_LOG << "HTMLMediaElement(" << (void*)this << ")";
 
-  // If any experiment is enabled, then we want to enable a user gesture by
-  // default, otherwise the experiment does nothing.
-  if ((document.settings() &&
-       document.settings()->mediaPlaybackRequiresUserGesture()) ||
-      m_autoplayHelper->isExperimentEnabled()) {
-    m_lockedPendingUserGesture = true;
-  }
+  m_lockedPendingUserGesture = computeLockedPendingUserGesture(document);
 
   LocalFrame* frame = document.frame();
   if (frame) {
@@ -519,13 +517,9 @@ void HTMLMediaElement::didMoveToNewDocument(Document& oldDocument) {
   // If any experiment is enabled, then we want to enable a user gesture by
   // default, otherwise the experiment does nothing.
   bool oldDocumentRequiresUserGesture =
-      (oldDocument.settings() &&
-       oldDocument.settings()->mediaPlaybackRequiresUserGesture()) ||
-      m_autoplayHelper->isExperimentEnabled();
+      computeLockedPendingUserGesture(oldDocument);
   bool newDocumentRequiresUserGesture =
-      (document().settings() &&
-       document().settings()->mediaPlaybackRequiresUserGesture()) ||
-      m_autoplayHelper->isExperimentEnabled();
+      computeLockedPendingUserGesture(document());
   if (newDocumentRequiresUserGesture && !oldDocumentRequiresUserGesture) {
     m_lockedPendingUserGesture = true;
   }
@@ -3886,6 +3880,21 @@ void HTMLMediaElement::selectInitialTracksIfNecessary() {
     videoTracks().anonymousIndexedGetter(0)->setSelected(true);
 }
 
+bool HTMLMediaElement::computeLockedPendingUserGesture(
+    Document& document) const {
+  // TODO(zqzhang): deprecate AutoplayExperiment. See https://crbug.com/666370
+  if (m_autoplayHelper->isExperimentEnabled())
+    return true;
+  if (!document.settings())
+    return false;
+
+  if (document.settings()->crossOriginMediaPlaybackRequiresUserGesture() &&
+      isDocumentCrossOrigin(document))
+    return true;
+
+  return document.settings()->mediaPlaybackRequiresUserGesture();
+}
+
 bool HTMLMediaElement::isLockedPendingUserGesture() const {
   return m_lockedPendingUserGesture;
 }