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 5703e89379df95dc4c5e99f77c0a60a1778c4ca6..1b123b73db2a6761014d7849f42996daf9c52de7 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -7378,6 +7378,17 @@ 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 79df3379152f0fa8d0bd00dc44dcc6c5fc60b089..46258346efd962f2484d4edafd69a1c8e13fcc7e 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3566,21 +3566,25 @@ 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) {
@@ -3712,7 +3716,7 @@ 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 32b4f5d0c0e75fc94d95298ef127c113330896b0..ae1b2ebef7c9620f465506a38855a585fd79ce48 100644
--- a/third_party/blink/renderer/core/fullscreen/fullscreen.cc
+++ b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
@@ -99,7 +99,7 @@ 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(