Add DCHECK(rootBox) to InlineFlowBox::computeLogicalBoxHeights

third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp

Index: third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
diff --git a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
index 19bf94a71263d6134c865cd25cde5e30b89de5b6..0bb27d46e6593bae0bf234349835fce0f85d932b 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
+++ b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
@@ -628,6 +628,7 @@ void InlineFlowBox::computeLogicalBoxHeights(
     // child box's baseline and the root box's baseline. The value is negative
     // if the child box's baseline is above the root box's baseline, and it is
     // positive if the child box's baseline is below the root box's baseline.
+    DCHECK(rootBox);
     curr->setLogicalTop(
         rootBox->verticalPositionForBox(curr, verticalPositionCache));