Turn on enforce-in-pdf Clang plugin flag.

pdf/paint_aggregator.h

Index: pdf/paint_aggregator.h
diff --git a/pdf/paint_aggregator.h b/pdf/paint_aggregator.h
index 74737ab8fb66b6b3165fa46fbb614bb30afcd522..5bb4ea72251f68e3d45b2f8fa175f297af8803ab 100644
--- a/pdf/paint_aggregator.h
+++ b/pdf/paint_aggregator.h
@@ -9,7 +9,6 @@
 
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/rect.h"
-#include "ppapi/cpp/rect.h"
 
 // This class is responsible for aggregating multiple invalidation and scroll
 // commands to produce a scroll and repaint sequence. You can use this manually
@@ -31,6 +30,7 @@ class PaintAggregator {
 
   struct PaintUpdate {
     PaintUpdate();
+    PaintUpdate(const PaintUpdate& that);
     ~PaintUpdate();
 
     // True if there is a scroll applied. This indicates that the scroll delta