Avoid syncing muted state with owner web_contents

fix brave/browser-laptop#13979
fix brave/browser-laptop#13996

Auditor: @bridiver

patches/master_patch.patch

@@ -1141,10 +1141,21 @@ index dbd2ae8df59756c61d28091cff70098c897db8f4..84fbc695c817c87deb902d8b6f69d3f1
        link.href = href;
        link.target = '_blank';
 diff --git a/components/guest_view/browser/guest_view_base.cc b/components/guest_view/browser/guest_view_base.cc
-index 865dec78f433ae6e526b10a6e0fce4631a944342..c95188210bf3699dacb0ab2ae823e2c951ef3c43 100644
+index 865dec78f433ae6e526b10a6e0fce4631a944342..e8d0153df7f48135f77c6783ecf8e423d04822b3 100644
 --- a/components/guest_view/browser/guest_view_base.cc
 +++ b/components/guest_view/browser/guest_view_base.cc
-@@ -437,8 +437,12 @@ void GuestViewBase::DidDetach() {
+@@ -416,8 +416,10 @@ void GuestViewBase::DidAttach(int guest_proxy_routing_id) {
+
+   SetUpSizing(*attach_params());
+
++#if defined(MUON_CHROMIUM_BUILD)
+   // The guest should have the same muting state as the owner.
+   web_contents()->SetAudioMuted(owner_web_contents()->IsAudioMuted());
++#endif
+
+   // Give the derived class an opportunity to perform some actions.
+   DidAttachToEmbedder();
+@@ -437,8 +439,12 @@ void GuestViewBase::DidDetach() {
    owner_web_contents()->GetRenderViewHost()->Send(
        new GuestViewMsg_GuestDetached(element_instance_id_));
    element_instance_id_ = kInstanceIDNone;