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 dd466e61b47c2bdf9652b5155b9c84ff2cd7352d..969b2eab8b6319d345a8b61082fba97bbd3c2fdf 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -6591,6 +6591,17 @@ void RenderFrameHostImpl::EnterFullscreen(
     }
   }
 
+  // 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);
+    if (outer_proxy->is_render_frame_proxy_live()) {
+      outer_proxy->GetAssociatedRemoteFrame()->WillEnterFullscreen(
+          options.Clone());
+    }
+  }
+
   // Focus the window if another frame may have delegated the capability.
   if (had_fullscreen_token && !GetView()->HasFocus())
     GetView()->Focus();