Turn on enforce-in-pdf Clang plugin flag.

pdf/paint_aggregator.cc

Index: pdf/paint_aggregator.cc
diff --git a/pdf/paint_aggregator.cc b/pdf/paint_aggregator.cc
index 50d77fe47d3569f71762cb2597c685d630ff9bcc..ba444cfdf995ea85c4d69648f936fb7c3ca807af 100644
--- a/pdf/paint_aggregator.cc
+++ b/pdf/paint_aggregator.cc
@@ -34,11 +34,11 @@ bool IsNegative(int32_t num) {
 // therefore be treated as an invalidation.
 // ----------------------------------------------------------------------------
 
-PaintAggregator::PaintUpdate::PaintUpdate() {
-}
+PaintAggregator::PaintUpdate::PaintUpdate() = default;
 
-PaintAggregator::PaintUpdate::~PaintUpdate() {
-}
+PaintAggregator::PaintUpdate::PaintUpdate(const PaintUpdate& that) = default;
+
+PaintAggregator::PaintUpdate::~PaintUpdate() = default;
 
 PaintAggregator::InternalPaintUpdate::InternalPaintUpdate() :
     synthesized_scroll_damage_rect_(false) {