Move line/continuation specific parts of willBeDestroyed() into LayoutBlockFlow.

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
index 05da9f52ff258034d2a171b764593ce50be1e535..73cc865650c7f1be92513e4c6041980ba164deed 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
@@ -91,6 +91,7 @@ public:
     ~LayoutBlockFlow() override;
 
     static LayoutBlockFlow* createAnonymous(Document*);
+    bool beingDestroyed() const { return m_beingDestroyed; }
 
     bool isLayoutBlockFlow() const final { return true; }
 
@@ -308,6 +309,7 @@ protected:
 
     void createFloatingObjects();
 
+    void willBeDestroyed() override;
     void styleWillChange(StyleDifference, const ComputedStyle& newStyle) override;
     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;