Fix crash when destroying a RenderWidgetHost that holds the pointer

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 23a03d9b75fac5e2fd7bb91fa7001bfe8296fbcc..59d1213b39a2ed7bb07686f7445af0adf97867de 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1707,8 +1707,7 @@ void WebContentsImpl::RenderWidgetDeleted(
       view_->RestoreFocus();
   }
 
-  if (mouse_lock_widget_ == render_widget_host)
-    mouse_lock_widget_ = nullptr;
+  CHECK(mouse_lock_widget_ != render_widget_host);
 }
 
 void WebContentsImpl::RenderWidgetGotFocus(
@@ -1897,12 +1896,19 @@ blink::WebDisplayMode WebContentsImpl::GetDisplayMode(
 void WebContentsImpl::RequestToLockMouse(
     RenderWidgetHostImpl* render_widget_host,
     bool user_gesture,
-    bool last_unlocked_by_target) {
+    bool last_unlocked_by_target,
+    bool privileged) {
   if (mouse_lock_widget_) {
     render_widget_host->GotResponseToLockMouseRequest(false);
     return;
   }
 
+  if (privileged) {
+    mouse_lock_widget_ = render_widget_host;
+    render_widget_host->GotResponseToLockMouseRequest(true);
+    return;
+  }
+
   bool widget_in_frame_tree = false;
   for (FrameTreeNode* node : frame_tree_.Nodes()) {
     if (node->current_frame_host()->GetRenderWidgetHost() ==
@@ -1929,6 +1935,14 @@ void WebContentsImpl::LostMouseLock(RenderWidgetHostImpl* render_widget_host) {
     delegate_->LostMouseLock();
 }
 
+bool WebContentsImpl::HasMouseLock(RenderWidgetHostImpl* render_widget_host) {
+  // To verify if the mouse is locked, the mouse_lock_widget_ needs to be
+  // assigned to the widget that requested the mouse lock, and the top-level
+  // platform RenderWidgetHostView needs to hold the mouse lock from the OS.
+  return mouse_lock_widget_ == render_widget_host &&
+         GetTopLevelRenderWidgetHostView()->IsMouseLocked();
+}
+
 void WebContentsImpl::ForwardCompositorProto(
     RenderWidgetHostImpl* render_widget_host,
     const std::vector<uint8_t>& proto) {
@@ -2986,8 +3000,11 @@ bool WebContentsImpl::GotResponseToLockMouseRequest(bool allowed) {
   if (GetBrowserPluginGuest())
     return GetBrowserPluginGuest()->LockMouse(allowed);
 
-  if (mouse_lock_widget_)
-    return mouse_lock_widget_->GotResponseToLockMouseRequest(allowed);
+  if (mouse_lock_widget_ &&
+      mouse_lock_widget_->GotResponseToLockMouseRequest(allowed))
+    return true;
+
+  mouse_lock_widget_ = nullptr;
   return false;
 }