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 4fc07868f9b6db2b634356dea8e329a191c8c139..6f9db0a2f37dcccd567cd946966f6e7bc7c9a94a 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -7486,6 +7486,17 @@ 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 96d503ae1cd7af461833cf643aef36b4455397a6..5a711c115ab7690409f2b32d8c332151c462254e 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3711,21 +3711,25 @@ 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) {
@@ -3861,7 +3865,7 @@ void WebContentsImpl::EnterFullscreenMode(
   OPTIONAL_TRACE_EVENT0("content", "WebContentsImpl::EnterFullscreenMode");
   DCHECK(CanEnterFullscreenMode(requesting_frame, options));
   DCHECK(requesting_frame->IsActive());
-  DCHECK(ContainsOrIsFocusedWebContents());
+  DCHECK(ContainsOrIsFocusedWebContents() || IsGuest());
 
   // When WebView is the `delegate_` we can end up with VisualProperties changes
   // synchronously. Notify the view ahead so it can handle the transition.
diff --git a/third_party/blink/renderer/core/fullscreen/fullscreen.cc b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
index 3d18b5a72a06c0ff1981ac6597d47a4bbe749b09..475c580d58df1a715937727dde2bed075ebffe70 100644
--- a/third_party/blink/renderer/core/fullscreen/fullscreen.cc
+++ b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
@@ -109,7 +109,7 @@ 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(