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.It also handles a
DCHECK preventing guest webcontents from becoming the focused webContents.

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 4f42cb8fc2d8347281debb8b34172c47676fc191..7224638f59aeccbb55043a9dea1295f849e34829 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -7505,6 +7505,17 @@ 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();
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 41c56be85c872d05b7b4300b242679659aa532bd..8fa03cce47dfb7680859e73b2858685e03cf6b3d 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3713,21 +3713,25 @@ KeyboardEventProcessingResult WebContentsImpl::PreHandleKeyboardEvent(
     const NativeWebKeyboardEvent& event) {
   OPTIONAL_TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("content.verbose"),
                         "WebContentsImpl::PreHandleKeyboardEvent");
-  auto* outermost_contents = GetOutermostWebContents();
-  // TODO(wjmaclean): Generalize this to forward all key events to the outermost
-  // delegate's handler.
-  if (outermost_contents != this && IsFullscreen() &&
-      event.windows_key_code == ui::VKEY_ESCAPE) {
-    // When an inner WebContents has focus and is fullscreen, redirect <esc>
-    // key events to the outermost WebContents so it can be handled by that
-    // WebContents' delegate.
-    if (outermost_contents->PreHandleKeyboardEvent(event) ==
-        KeyboardEventProcessingResult::HANDLED) {
+
+  auto handled = delegate_ ? delegate_->PreHandleKeyboardEvent(this, event)
+                   : KeyboardEventProcessingResult::NOT_HANDLED;
+
+  if (IsFullscreen() && event.windows_key_code == ui::VKEY_ESCAPE) {
+    if (handled == KeyboardEventProcessingResult::HANDLED)
       return KeyboardEventProcessingResult::HANDLED;
+
+    // When an inner WebContents has focus and is fullscreen, traverse through
+    // containing webcontents to any that may handle the escape key.
+    while (auto* outer_web_contents = GetOuterWebContents()) {
+      auto result = outer_web_contents->PreHandleKeyboardEvent(event);
+      if (result == KeyboardEventProcessingResult::HANDLED) {
+        return KeyboardEventProcessingResult::HANDLED;
+      }
     }
   }
-  return delegate_ ? delegate_->PreHandleKeyboardEvent(this, event)
-                   : KeyboardEventProcessingResult::NOT_HANDLED;
+
+  return handled;
 }
 
 bool WebContentsImpl::HandleMouseEvent(const blink::WebMouseEvent& event) {
@@ -3863,7 +3867,7 @@ void WebContentsImpl::EnterFullscreenMode(
   OPTIONAL_TRACE_EVENT0("content", "WebContentsImpl::EnterFullscreenMode");
   DCHECK(CanEnterFullscreenMode(requesting_frame, options));
   DCHECK(requesting_frame->IsActive());
-  DCHECK(ContainsOrIsFocusedWebContents());
+  DCHECK(ContainsOrIsFocusedWebContents() || IsGuest());
   if (base::FeatureList::IsEnabled(
           features::kAutomaticFullscreenContentSetting)) {
     // Ensure the window is made active to take input focus. The user may have
diff --git a/third_party/blink/renderer/core/fullscreen/fullscreen.cc b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
index 0135a5340b1d1b81fc47a10abe362f5efdd0f222..488d04a9c40deabab47d6235dc36537f47b5d530 100644
--- a/third_party/blink/renderer/core/fullscreen/fullscreen.cc
+++ b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
@@ -111,7 +111,7 @@ void FullscreenElementChanged(Document& document,
     // is the iframe element for the out-of-process frame that contains the
     // fullscreen element. Hence, it must match :-webkit-full-screen-ancestor.
     if (new_request_type & FullscreenRequestType::kForCrossProcessDescendant) {
-      DCHECK(IsA<HTMLIFrameElement>(new_element));
+      // DCHECK(IsA<HTMLIFrameElement>(new_element));
       new_element->SetContainsFullScreenElement(true);
     }
     new_element->SetContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(