Make the PPP wrappers take an Instance*.

ppapi/cpp/dev/printing_dev.h

Index: ppapi/cpp/dev/printing_dev.h
diff --git a/ppapi/cpp/dev/printing_dev.h b/ppapi/cpp/dev/printing_dev.h
index c2b6b057542f55a93403a1a8000e6fad683d0697..734015f4d3d72b1fce816c59c000135dfd4ff998 100644
--- a/ppapi/cpp/dev/printing_dev.h
+++ b/ppapi/cpp/dev/printing_dev.h
@@ -11,12 +11,14 @@
 
 namespace pp {
 
+class Instance;
+
 // You would typically use this either via inheritance on your instance or
 // by composition: see find_dev.h for an example.
 class Printing_Dev {
  public:
   // The instance parameter must outlive this class.
-  explicit Printing_Dev(const InstanceHandle& instance);
+  explicit Printing_Dev(Instance* instance);
   virtual ~Printing_Dev();
 
   // PPP_Printing_Dev functions exposed as virtual functions for you to