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 ec3a51fcd891841f945b4f3629968330f25dd1c0..a0c056f47b9582536f9c8ee93517c872bfadf2e3 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -5844,6 +5844,15 @@ 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, true /* is_fullscreen */,
                                     std::move(options));
