Propagate inert state to OOPIFs when a modal dialog is active

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

Index: third_party/WebKit/Source/core/frame/LocalFrame.h
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.h b/third_party/WebKit/Source/core/frame/LocalFrame.h
index 45f9220e33ba3ec265d56961cc2bd8ad8783be00..eda02a121a9bec6a2c086a15527cd6feb55f8c3d 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.h
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.h
@@ -234,6 +234,9 @@ class CORE_EXPORT LocalFrame final : public Frame,
   // the embedder decides that Client Lo-Fi should be used for this request.
   void MaybeAllowImagePlaceholder(FetchParameters&) const;
 
+  bool IsInert() const { return is_inert_; }
+  void SetIsInert(bool inert);
+
   using FrameInitCallback = void (*)(LocalFrame*);
   // Allows for the registration of a callback that is invoked whenever a new
   // LocalFrame is initialized. Callbacks are executed in the order that they
@@ -284,6 +287,8 @@ class CORE_EXPORT LocalFrame final : public Frame,
 
   bool in_view_source_mode_;
 
+  bool is_inert_;
+
   Member<CoreProbeSink> instrumenting_agents_;
   Member<PerformanceMonitor> performance_monitor_;