Fix dangling pointer to native_delegate_(fix issue chromiumembedded#4072)

Change native_delegate_ within ChildWindowDelegate to be base::WeakPtr<CefBrowserPlatformDelegateNative> to fix dangling pointer.

Author: JCYang

libcef/browser/chrome/browser_platform_delegate_chrome.h

@@ -52,8 +52,8 @@ class CefBrowserPlatformDelegateChrome
 
   void set_chrome_browser(Browser* browser);
 
-  CefBrowserPlatformDelegateNative* native_delegate() const {
-    return native_delegate_.get();
+  base::WeakPtr<CefBrowserPlatformDelegateNative> native_delegate() const {
+    return native_delegate_->GetWeakPtr();
   }
 
  protected:

libcef/browser/chrome/views/chrome_child_window.cc

@@ -65,7 +65,7 @@ class ChildWindowDelegate : public CefWindowDelegate {
   void OnWindowDestroyed(CefRefPtr<CefWindow> window) override {
     browser_view_ = nullptr;
     window_ = nullptr;
-#if BUILDFLAG(IS_WIN)
+#if defined(USE_AURA)
     native_delegate_ = nullptr;
 #endif
   }
@@ -96,8 +96,7 @@ class ChildWindowDelegate : public CefWindowDelegate {
     DCHECK(platform_delegate->IsViewsHosted());
     auto chrome_delegate =
         static_cast<CefBrowserPlatformDelegateChromeViews*>(platform_delegate);
-    native_delegate_ = static_cast<CefBrowserPlatformDelegateNativeAura*>(
-        chrome_delegate->native_delegate());
+    native_delegate_ = chrome_delegate->native_delegate();
 
 #if BUILDFLAG(IS_WIN)
     auto widget = static_cast<CefWindowImpl*>(window_.get())->widget();
@@ -106,9 +105,11 @@ class ChildWindowDelegate : public CefWindowDelegate {
     DCHECK(widget_hwnd);
 
     // The Windows delegate needs state to perform some actions.
-    auto* delegate_win =
-        static_cast<CefBrowserPlatformDelegateNativeWin*>(native_delegate_);
-    delegate_win->set_widget(widget, widget_hwnd);
+    if (native_delegate_){
+      auto* delegate_win =
+          static_cast<CefBrowserPlatformDelegateNativeWin*>(native_delegate_);
+      delegate_win->set_widget(widget, widget_hwnd);
+    }
 
     if (window_info_.ex_style & WS_EX_NOACTIVATE) {
       const DWORD widget_ex_styles = GetWindowLongPtr(widget_hwnd, GWL_EXSTYLE);
@@ -145,7 +146,7 @@ class ChildWindowDelegate : public CefWindowDelegate {
   CefRefPtr<CefWindow> window_;
 
 #if defined(USE_AURA)
-  base::raw_ptr<CefBrowserPlatformDelegateNativeAura> native_delegate_ =
+  base::WeakPtr<CefBrowserPlatformDelegateNative> native_delegate_ =
       nullptr;
 #endif
 

libcef/browser/native/browser_platform_delegate_native.cc

@@ -47,3 +47,7 @@ void CefBrowserPlatformDelegateNative::NotifyScreenInfoChanged() {
 
   render_widget_host->NotifyScreenInfoChanged();
 }
+
+base::WeakPtr<CefBrowserPlatformDelegateNative> CefBrowserPlatformDelegateNative::GetWeakPtr() {
+  return weak_ptr_factory_.GetWeakPtr();
+}

libcef/browser/native/browser_platform_delegate_native.h

@@ -51,7 +51,7 @@ class CefBrowserPlatformDelegateNative
       int deltaY) const = 0;
 
   const CefWindowInfo& window_info() const { return window_info_; }
-
+  base::WeakPtr<CefBrowserPlatformDelegateNative> GetWeakPtr();
  protected:
   // Delegates that can wrap a native delegate.
   friend class CefBrowserPlatformDelegateBackground;
@@ -73,6 +73,9 @@ class CefBrowserPlatformDelegateNative
 
   // Not owned by this object.
   raw_ptr<WindowlessHandler> windowless_handler_ = nullptr;
+
+  base::WeakPtrFactory<CefBrowserPlatformDelegateNative> weak_ptr_factory_{
+      this};
 };
 
 #endif  // CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_