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 47e9082e168a5930ac9548c9bdc6f8c03a8ef10c..99d364f7d05b74102d3dc5d2f596cb8b0e3bd824 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.h
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.h
@@ -237,6 +237,11 @@ class CORE_EXPORT LocalFrame final : public Frame,
 
   std::unique_ptr<WebURLLoader> CreateURLLoader();
 
+  // This sets the is_inert_ flag and also recurses through this frame's
+  // subtree, updating the inert bit on all descendant frames.
+  void SetIsInert(bool inert);
+  bool IsInert() const { return is_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
@@ -287,6 +292,8 @@ class CORE_EXPORT LocalFrame final : public Frame,
 
   bool in_view_source_mode_;
 
+  bool is_inert_;
+
   Member<CoreProbeSink> probe_sink_;
   Member<PerformanceMonitor> performance_monitor_;