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 a248259b4cb999fb980df8589f41aa61e02b6131..bc33e60dd9e6efe97254cdbe9ed4a06d653afb81 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -7725,6 +7725,17 @@ 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 5ade124fabe47ccaaa2abef44a06483e7815b863..c55bb2fd33aeaea3515dd1612d60e9b8c787ddb9 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3912,21 +3912,25 @@ KeyboardEventProcessingResult WebContentsImpl::PreHandleKeyboardEvent(
     const input::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) {
@@ -4084,7 +4088,7 @@ void WebContentsImpl::EnterFullscreenMode(
   OPTIONAL_TRACE_EVENT0("content", "WebContentsImpl::EnterFullscreenMode");
   DCHECK(CanEnterFullscreenMode(requesting_frame));
   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 5cb222aa469134e03af008f52e5e95fd5e2e2053..1b5fe8416277addbd3ef769f15ae0e1812f7c9f4 100644
--- a/third_party/blink/renderer/core/fullscreen/fullscreen.cc
+++ b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
@@ -112,7 +112,7 @@ 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(