Don't send PP_Vars/V8 values with cycles across PostMessage

ppapi/proxy/serialized_var.h

Index: ppapi/proxy/serialized_var.h
diff --git a/ppapi/proxy/serialized_var.h b/ppapi/proxy/serialized_var.h
index 98cafa0dac3afe009b54e821ec53dbaa063fa768..0b8e7966738b71246b6492e5727caf6dbc89a194 100644
--- a/ppapi/proxy/serialized_var.h
+++ b/ppapi/proxy/serialized_var.h
@@ -80,12 +80,24 @@ class PPAPI_PROXY_EXPORT SerializedVar {
   void WriteToMessage(IPC::Message* m) const {
     inner_->WriteToMessage(m);
   }
+  // If ReadFromMessage has been called, WriteDataToMessage will write the var
+  // that has been read from ReadFromMessage back to a message. This is used
+  // when converting handles for use in NaCl.
+  void WriteDataToMessage(IPC::Message* m,
+                          const HandleWriter& handle_writer) const {
+    inner_->WriteDataToMessage(m, handle_writer);
+  }
   bool ReadFromMessage(const IPC::Message* m, PickleIterator* iter) {
     return inner_->ReadFromMessage(m, iter);
   }
 
-  RawVarDataGraph* raw_var_data() const {
-    return inner_->raw_var_data();
+  bool is_valid_var() const {
+    return inner_->is_valid_var();
+  }
+
+  // Returns the shared memory handles associated with this SerializedVar.
+  std::vector<SerializedHandle*> GetHandles() const {
+    return inner_->GetHandles();
   }
 
  protected:
@@ -110,8 +122,13 @@ class PPAPI_PROXY_EXPORT SerializedVar {
       serialization_rules_ = serialization_rules;
     }
 
-    RawVarDataGraph* raw_var_data() {
-      return raw_var_data_.get();
+    bool is_valid_var() const {
+      return is_valid_var_;
+    }
+
+    std::vector<SerializedHandle*> GetHandles() {
+      return (raw_var_data_ ? raw_var_data_->GetHandles() :
+          std::vector<SerializedHandle*>());
     }
 
     // See outer class's declarations above.
@@ -124,6 +141,8 @@ class PPAPI_PROXY_EXPORT SerializedVar {
     void ForceSetVarValueForTest(PP_Var value);
 
     void WriteToMessage(IPC::Message* m) const;
+    void WriteDataToMessage(IPC::Message* m,
+                            const HandleWriter& handle_writer) const;
     bool ReadFromMessage(const IPC::Message* m, PickleIterator* iter);
 
     // Sets the cleanup mode. See the CleanupMode enum below.
@@ -162,6 +181,9 @@ class PPAPI_PROXY_EXPORT SerializedVar {
 
     CleanupMode cleanup_mode_;
 
+    // If the var is not properly serialized, this will be false.
+    bool is_valid_var_;
+
 #ifndef NDEBUG
     // When being sent or received over IPC, we should only be serialized or
     // deserialized once. These flags help us assert this is true.
@@ -342,6 +364,7 @@ class PPAPI_PROXY_EXPORT SerializedVarReceiveInput {
 
   PP_Var Get(Dispatcher* dispatcher);
   PP_Var GetForInstance(Dispatcher* dispatcher, PP_Instance instance);
+  bool is_valid_var() { return serialized_.is_valid_var(); }
 
  private:
   const SerializedVar& serialized_;