fix: update and enable osr (#15046)

* fix: update and enable osr

* fix: update MacHelper view to call GetNativeView

* style: move stuff around to make more sense

* chore: move OSR related things in SetOwnerWindow to CommonWebContentsDelegate

* fix: avoid crashing when GetOffscreenRenderWidgetHostView is called

* fix: specify default for current_device_scale_factor_

atom/browser/common_web_contents_delegate.h

@@ -16,6 +16,7 @@
 #include "brightray/browser/inspectable_web_contents_view_delegate.h"
 #include "chrome/browser/devtools/devtools_file_system_indexer.h"
 #include "content/public/browser/web_contents_delegate.h"
+#include "electron/buildflags/buildflags.h"
 
 #if defined(TOOLKIT_VIEWS) && !defined(OS_MACOSX)
 #include "atom/browser/ui/autofill_popup.h"
@@ -31,6 +32,10 @@ class AtomBrowserContext;
 class NativeWindow;
 class WebDialogHelper;
 
+#if BUILDFLAG(ENABLE_OSR)
+class OffScreenRenderWidgetHostView;
+#endif
+
 class CommonWebContentsDelegate
     : public content::WebContentsDelegate,
       public brightray::InspectableWebContentsDelegate,
@@ -65,6 +70,11 @@ class CommonWebContentsDelegate
   bool is_html_fullscreen() const { return html_fullscreen_; }
 
  protected:
+#if BUILDFLAG(ENABLE_OSR)
+  virtual OffScreenRenderWidgetHostView* GetOffScreenRenderWidgetHostView()
+      const;
+#endif
+
   // content::WebContentsDelegate:
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,