From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Thu, 4 Oct 2018 14:57:02 -0700
Subject: fix: also propagate fullscreen state for outer frame

When entering fullscreen with Element.requestFullscreen in child frames,
the parent frame should also enter fullscreen mode too. Chromium handles
this for iframes, but not for webviews as they are essentially main
frames instead of child frames.

This patch makes webviews propagate the fullscreen state to embedder.

Note that we also need to manually update embedder's
`api::WebContents::IsFullscreenForTabOrPending` value.

diff --git a/content/browser/renderer_host/render_frame_host_impl.cc b/content/browser/renderer_host/render_frame_host_impl.cc
index 713e2883139bca4bb56dcc7e3efcf6d6dfc4a02b..be2721cc6dc0582a05c74ac3d50c123666d7d5a3 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -6102,6 +6102,15 @@ void RenderFrameHostImpl::EnterFullscreen(
     notified_instances.insert(parent_site_instance);
   }
 
+  // Entering fullscreen from webview should also notify its outer frame.
+  if (frame_tree_node()->render_manager()->IsMainFrameForInnerDelegate()) {
+    RenderFrameProxyHost* outer_proxy =
+        frame_tree_node()->render_manager()->GetProxyToOuterDelegate();
+    DCHECK(outer_proxy);
+    outer_proxy->GetAssociatedRemoteFrame()->WillEnterFullscreen(
+        options.Clone());
+  }
+
   delegate_->EnterFullscreenMode(this, *options);
   delegate_->FullscreenStateChanged(this, /*is_fullscreen=*/true,
                                     std::move(options));