Check that a valid RawVarData has been created before calling a function on it

ppapi/proxy/raw_var_data.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/proxy/raw_var_data.h"
 
 #include <stack>
 
 #include "base/containers/hash_tables.h"
 #include "base/memory/ptr_util.h"
@@ skipping 180 matching lines @@
   std::unique_ptr<RawVarDataGraph> result(new RawVarDataGraph);
   uint32_t size = 0;
   if (!iter->ReadUInt32(&size))
     return nullptr;
   for (uint32_t i = 0; i < size; ++i) {
     int32_t type;
     if (!iter->ReadInt(&type))
       return nullptr;
     PP_VarType var_type = static_cast<PP_VarType>(type);
     result->data_.push_back(base::WrapUnique(RawVarData::Create(var_type)));
+    if (!result->data_.back())
+      return nullptr;
     if (!result->data_.back()->Read(var_type, m, iter))
       return nullptr;
   }
   return result;
 }
 
 std::vector<SerializedHandle*> RawVarDataGraph::GetHandles() {
   std::vector<SerializedHandle*> result;
   for (size_t i = 0; i < data_.size(); ++i) {
     SerializedHandle* handle = data_[i]->GetHandle();
@@ skipping 529 matching lines @@
     if (!IPC::ReadParam(m, iter, creation_message_.get()))
       return false;
   } else {
     creation_message_.reset();
   }
   return true;
 }
 
 }  // namespace proxy
 }  // namespace ppapi