2 files changed, 16 insertions, 0 deletions
diff --git a/layout/generic/ReflowInput.cpp b/layout/generic/ReflowInput.cpp
index f308ebcdf5..01f36cc9db 100644
--- a/layout/generic/ReflowInput.cpp
+++ b/layout/generic/ReflowInput.cpp
@@ -2813,6 +2813,17 @@ nscoord ReflowInput::GetLineHeight() const {
                                nsLayoutUtils::FontSizeInflationFor(mFrame));
 }
 
+void ReflowInput::SetLineHeight(nscoord aLineHeight) {
+  MOZ_ASSERT(aLineHeight >= 0, "aLineHeight must be >= 0!");
+
+  if (mLineHeight != aLineHeight) {
+    mLineHeight = aLineHeight;
+    // Setting used line height can change a frame's block-size if mFrame's
+    // block-size behaves as auto.
+    InitResizeFlags(mFrame->PresContext(), mFrame->GetType());
+  }
+}
+
 /* static */ nscoord
 ReflowInput::CalcLineHeight(nsIContent* aContent,
                                   nsStyleContext* aStyleContext,
diff --git a/layout/generic/ReflowInput.h b/layout/generic/ReflowInput.h
index d8e0518399..a70549d8eb 100644
--- a/layout/generic/ReflowInput.h
+++ b/layout/generic/ReflowInput.h
@@ -747,6 +747,11 @@ public:
    * Get the used line-height property. The return value will be >= 0.
    */
   nscoord GetLineHeight() const;
+  
+  /**
+   * Set the used line-height. aLineHeight must be >= 0.
+   */
+  void SetLineHeight(nscoord aLineHeight);
 
   /**
    * Calculate the used line-height property without a reflow input instance.