third_party/WebKit: fix typos found in comments

third_party/WebKit/Source/core/paint/PaintLayer.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index ded24777fc93352efa5270495cbf6fd8340df234..44954b772a71141cb1036022d064a5e48977288b 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -2280,7 +2280,7 @@ void PaintLayer::ensureCompositedLayerMapping()
 void PaintLayer::clearCompositedLayerMapping(bool layerBeingDestroyed)
 {
     if (!layerBeingDestroyed) {
-        // We need to make sure our decendants get a geometry update. In principle,
+        // We need to make sure our descendants get a geometry update. In principle,
         // we could call setNeedsGraphicsLayerUpdate on our children, but that would
         // require walking the z-order lists to find them. Instead, we over-invalidate
         // by marking our parent as needing a geometry update.