6 files changed, 45 insertions, 0 deletions
diff --git a/ppapi/cpp/dev/truetype_font_dev.h b/ppapi/cpp/dev/truetype_font_dev.h
index cdaeade..bd554f7 100644
--- a/ppapi/cpp/dev/truetype_font_dev.h
+++ b/ppapi/cpp/dev/truetype_font_dev.h
@@ -208,6 +208,12 @@ struct CallbackOutputTraits<TrueTypeFontDesc_Dev> {
   static inline TrueTypeFontDesc_Dev StorageToPluginArg(StorageType& t) {
     return TrueTypeFontDesc_Dev(PASS_REF, t);
   }
+
+  static inline void Initialize(StorageType* t) {
+    // Use the same defaults as TrueTypeFontDesc_Dev does.
+    TrueTypeFontDesc_Dev dummy;
+    *t = dummy.pp_desc();
+  }
 };
 
 class TrueTypeFontDescArrayOutputAdapterWithStorage
@@ -255,6 +261,8 @@ struct CallbackOutputTraits< std::vector<TrueTypeFontDesc_Dev> > {
       StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 }  // namespace internal
diff --git a/ppapi/cpp/directory_entry.h b/ppapi/cpp/directory_entry.h
index 81be79e..bf3d845 100644
--- a/ppapi/cpp/directory_entry.h
+++ b/ppapi/cpp/directory_entry.h
@@ -119,6 +119,8 @@ struct CallbackOutputTraits< std::vector<DirectoryEntry> > {
       StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 }  // namespace internal
diff --git a/ppapi/cpp/extensions/ext_output_traits.h b/ppapi/cpp/extensions/ext_output_traits.h
index 08dc744c..ed57be1 100644
--- a/ppapi/cpp/extensions/ext_output_traits.h
+++ b/ppapi/cpp/extensions/ext_output_traits.h
@@ -68,6 +68,8 @@ struct ExtCallbackOutputTraits {
   static inline T& StorageToPluginArg(StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 // This class provides storage for a PP_Var and a vector of objects which are
@@ -129,6 +131,8 @@ struct ExtCallbackOutputTraits< std::vector<T> > {
   static inline std::vector<T>& StorageToPluginArg(StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 }  // namespace internal
diff --git a/ppapi/cpp/output_traits.h b/ppapi/cpp/output_traits.h
index 1779e7a..37a8a65 100644
--- a/ppapi/cpp/output_traits.h
+++ b/ppapi/cpp/output_traits.h
@@ -85,6 +85,10 @@ struct GenericCallbackOutputTraits {
   // callbacks. This doesn't actually need to do anything in this case,
   // it's needed for some of more complex template specializations below.
   static inline T& StorageToPluginArg(StorageType& t) { return t; }
+
+  // Initializes the "storage type" to a default value, if necessary. Here,
+  // we do nothing, assuming that the default constructor for T suffices.
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 // Output traits for all resource types. It is implemented to pass a
@@ -113,6 +117,10 @@ struct ResourceCallbackOutputTraits {
   static inline T StorageToPluginArg(StorageType& t) {
     return T(PASS_REF, t);
   }
+
+  static inline void Initialize(StorageType* t) {
+    *t = 0;
+  }
 };
 
 // The general templatized base class for all CallbackOutputTraits. This class
@@ -147,6 +155,10 @@ struct CallbackOutputTraits<Var> {
   static inline pp::Var StorageToPluginArg(StorageType& t) {
     return Var(PASS_REF, t);
   }
+
+  static inline void Initialize(StorageType* t) {
+    *t = PP_MakeUndefined();
+  }
 };
 
 // Array output parameters -----------------------------------------------------
@@ -175,6 +187,8 @@ struct GenericVectorCallbackOutputTraits {
   static inline std::vector<T>& StorageToPluginArg(StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 // Output traits for all vectors of resource types. It is implemented to pass
@@ -196,6 +210,8 @@ struct ResourceVectorCallbackOutputTraits {
   static inline std::vector<T>& StorageToPluginArg(StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 // Specialization of CallbackOutputTraits for vectors. This struct covers both
@@ -233,6 +249,8 @@ struct CallbackOutputTraits< std::vector<pp::Var> > {
   static inline std::vector<pp::Var>& StorageToPluginArg(StorageType& t) {
     return t.output();
   }
+
+  static inline void Initialize(StorageType* /* t */) {}
 };
 
 }  // namespace internal
diff --git a/ppapi/cpp/private/pass_file_handle.h b/ppapi/cpp/private/pass_file_handle.h
index 53f32dd..c25353b 100644
--- a/ppapi/cpp/private/pass_file_handle.h
+++ b/ppapi/cpp/private/pass_file_handle.h
@@ -5,6 +5,8 @@
 #ifndef PPAPI_CPP_PRIVATE_PASS_FILE_HANDLE_H_
 #define PPAPI_CPP_PRIVATE_PASS_FILE_HANDLE_H_
 
+#include <string.h>
+
 #include "ppapi/c/private/pp_file_handle.h"
 #include "ppapi/cpp/output_traits.h"
 
@@ -67,6 +69,10 @@ struct CallbackOutputTraits<PassFileHandle> {
   static inline PassFileHandle StorageToPluginArg(StorageType& t) {
     return PassFileHandle(t);
   }
+
+  static inline void Initialize(StorageType* t) {
+    memset(t, 0, sizeof(*t));
+  }
 };
 
 }  // namespace internal
diff --git a/ppapi/cpp/private/video_frame_private.h b/ppapi/cpp/private/video_frame_private.h
index fed9d1d..7413876 100644
--- a/ppapi/cpp/private/video_frame_private.h
+++ b/ppapi/cpp/private/video_frame_private.h
@@ -5,6 +5,8 @@
 #ifndef PPAPI_CPP_PRIVATE_VIDEO_FRAME_PRIVATE_H_
 #define PPAPI_CPP_PRIVATE_VIDEO_FRAME_PRIVATE_H_
 
+#include <string.h>
+
 #include "ppapi/c/pp_time.h"
 #include "ppapi/c/private/pp_video_frame_private.h"
 #include "ppapi/cpp/completion_callback.h"
@@ -87,6 +89,11 @@ struct CallbackOutputTraits<pp::VideoFrame_Private> {
   static inline pp::VideoFrame_Private StorageToPluginArg(StorageType& t) {
     return pp::VideoFrame_Private(PASS_REF, t);
   }
+
+  static inline void Initialize(StorageType* t) {
+    VideoFrame_Private dummy;
+    *t = dummy.pp_video_frame();
+  }
 };
 
 }  // namespace internal