Unrevert 58354, reland PPAPI with the instance test disabled.

webkit/glue/plugins/pepper_var.h

Index: webkit/glue/plugins/pepper_var.h
===================================================================
--- webkit/glue/plugins/pepper_var.h	(revision 58357)
+++ webkit/glue/plugins/pepper_var.h	(working copy)
@@ -26,6 +26,10 @@
 // function multiple times given the same NPObject results in the same PP_Var.
 PP_Var NPObjectToPPVar(NPObject* object);
 
+// Returns a PP_Var that corresponds to the given NPVariant.  The contents of
+// the NPVariant will be copied unless the NPVariant corresponds to an object.
+PP_Var NPVariantToPPVar(const NPVariant* variant);
+
 // Returns the NPObject corresponding to the PP_Var.  This pointer has not been
 // retained, so you should not call WebBindings::releaseObject unless you first
 // call WebBindings::retainObject.  Returns NULL if the PP_Var is not an object
@@ -42,6 +46,30 @@
 // a string type.
 String* GetString(PP_Var var);
 
+// Instantiate this object on the stack to catch V8 exceptions and pass them
+// to an optional out parameter supplied by the plugin.
+class TryCatch {
+ public:
+  // The given exception may be NULL if the consumer isn't interested in
+  // catching exceptions. If non-NULL, the given var will be updated if any
+  // exception is thrown (so it must outlive the TryCatch object).
+  TryCatch(PP_Var* exception);
+  ~TryCatch();
+
+  // Returns true is an exception has been thrown. This can be true immediately
+  // after construction if the var passed to the constructor is non-void.
+  bool HasException() const;
+
+  // Sets the given exception.
+  void SetException(const char* message);
+
+ private:
+  static void Catch(void* self, const char* message);
+
+  // May be null if the consumer isn't interesting in catching exceptions.
+  PP_Var* exception_;
+};
+
 }  // namespace pepper
 
 #endif  // WEBKIT_GLUE_PLUGINS_PEPPER_VAR_H_