Make the PPP wrappers take an Instance*.

ppapi/cpp/dev/printing_dev.cc

Index: ppapi/cpp/dev/printing_dev.cc
diff --git a/ppapi/cpp/dev/printing_dev.cc b/ppapi/cpp/dev/printing_dev.cc
index 26fff41f677ae70446547bc0f1a36a1b3ed5a7a0..72affff56a1f27872d40e7033793799fc8290b3e 100644
--- a/ppapi/cpp/dev/printing_dev.cc
+++ b/ppapi/cpp/dev/printing_dev.cc
@@ -70,10 +70,10 @@ const PPP_Printing_Dev ppp_printing = {
 
 }  // namespace
 
-Printing_Dev::Printing_Dev(const InstanceHandle& instance)
+Printing_Dev::Printing_Dev(Instance* instance)
       : associated_instance_(instance) {
   Module::Get()->AddPluginInterface(kPPPPrintingInterface, &ppp_printing);
-  Instance::AddPerInstanceObject(instance, kPPPPrintingInterface, this);
+  instance->AddPerInstanceObject(kPPPPrintingInterface, this);
 }
 
 Printing_Dev::~Printing_Dev() {