feat: enable picture-in-picture mode for video tags (#17686)

* feat: enable picture in picture mode for video tags

* test: add test to verify picture in picture support

* lint: fix indent

* fix: clean up after rebase

* test: update test with 16:9 test video

* fix: .paches after rebase

shell/browser/feature_list.cc

@@ -10,6 +10,8 @@
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "content/public/common/content_features.h"
+#include "electron/buildflags/buildflags.h"
+#include "media/base/media_switches.h"
 
 namespace electron {
 
@@ -25,6 +27,9 @@ void InitializeFeatureList() {
   // when node integration is enabled.
   disable_features +=
       std::string(",") + features::kSpareRendererForSitePerProcess.name;
+#if !BUILDFLAG(ENABLE_PICTURE_IN_PICTURE)
+  disable_features += std::string(",") + media::kPictureInPicture.name;
+#endif
   base::FeatureList::InitializeInstance(enable_features, disable_features);
 }