Add a WebRect version of invalidateRect to WebLayerImplFixedBounds

cc/blink/web_layer_impl_fixed_bounds.cc

Index: cc/blink/web_layer_impl_fixed_bounds.cc
diff --git a/cc/blink/web_layer_impl_fixed_bounds.cc b/cc/blink/web_layer_impl_fixed_bounds.cc
index 5ffb660ccbbaad32745b439da78e65409030edf1..e9e11c142c4d0560457cabc8c066a39f6a696aef 100644
--- a/cc/blink/web_layer_impl_fixed_bounds.cc
+++ b/cc/blink/web_layer_impl_fixed_bounds.cc
@@ -29,6 +29,12 @@ void WebLayerImplFixedBounds::invalidateRect(const blink::WebFloatRect& rect) {
   invalidate();
 }
 
+void WebLayerImplFixedBounds::invalidateRect(const blink::WebRect& rect) {
+  // Partial invalidations seldom occur for such layers.
+  // Simply invalidate the whole layer to avoid transformation of coordinates.
+  invalidate();
+}
+
 void WebLayerImplFixedBounds::setTransformOrigin(
     const blink::WebFloatPoint3D& transform_origin) {
   if (transform_origin != this->transformOrigin()) {