Fix resource leaks in CDM implementation.

ppapi/cpp/dev/buffer_dev.h

Index: ppapi/cpp/dev/buffer_dev.h
diff --git a/ppapi/cpp/dev/buffer_dev.h b/ppapi/cpp/dev/buffer_dev.h
index da89cbaee58ca83992dbe9dc4898a1251c35720d..d82f92d5cc8dd4e5de9abe6edb20efbead6f038f 100644
--- a/ppapi/cpp/dev/buffer_dev.h
+++ b/ppapi/cpp/dev/buffer_dev.h
@@ -22,6 +22,10 @@ class Buffer_Dev : public Resource {
   // resulting object will be is_null() if either Create() or Map() fails.
   Buffer_Dev(const InstanceHandle& instance, uint32_t size);
 
+  // Constructor used when the buffer resource already has a reference count
+  // assigned. No additional reference is taken.
+  Buffer_Dev(PassRef, PP_Resource resource);
+
   // Unmap the underlying shared memory.
   virtual ~Buffer_Dev();