Propagate inert state to OOPIFs when a modal dialog is active

third_party/WebKit/Source/core/frame/LocalFrame.cpp

Index: third_party/WebKit/Source/core/frame/LocalFrame.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 3eefa4fb1b4e989b32a932a7221951863416ce44..af2d790a62a58feef4a6202c0b3a1b1600da890e 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
@@ -572,6 +572,27 @@ void LocalFrame::DidChangeVisibilityState() {
   Frame::DidChangeVisibilityState();
 }
 
+void LocalFrame::SetIsInert(bool inert) {
+  is_inert_ = inert;
+  PropagateInertToChildFrames();
+}
+
+void LocalFrame::PropagateInertToChildFrames() {
+  for (Frame* child = Tree().FirstChild(); child;
+       child = child->Tree().NextSibling()) {
+    if (child->Owner()) {
+      DCHECK(child->Owner()->IsLocal());
+      // Only propagate if there is a change to the child's inert bit. This
+      // prevents redundant recursions through the Frame tree during style
+      // calculation.
+      bool new_value =
+          is_inert_ || ToHTMLFrameOwnerElement(child->Owner())->IsInert();
+      if (new_value != child->IsInert())
+        child->SetIsInert(new_value);
+    }
+  }
+}
+
 LocalFrame& LocalFrame::LocalFrameRoot() const {
   const LocalFrame* cur_frame = this;
   while (cur_frame && cur_frame->Tree().Parent() &&
@@ -899,6 +920,7 @@ inline LocalFrame::LocalFrame(LocalFrameClient* client,
       page_zoom_factor_(ParentPageZoomFactor(this)),
       text_zoom_factor_(ParentTextZoomFactor(this)),
       in_view_source_mode_(false),
+      is_inert_(false),
       interface_provider_(interface_provider),
       interface_registry_(interface_registry) {
   if (IsLocalRoot()) {