Fix various memory leaks in unit tests detected by a new version of ASAN.

runtime/vm/native_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_message.h"
 #include "vm/dart_api_state.h"
 #include "vm/message.h"
 #include "vm/native_message_handler.h"
 #include "vm/port.h"
 
 namespace dart {
 
 // --- Message sending/receiving from native code ---
 
-static uint8_t* allocator(uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
+static uint8_t* malloc_allocator(uint8_t* ptr,
+                                 intptr_t old_size,
+                                 intptr_t new_size) {
   void* new_ptr = realloc(reinterpret_cast<void*>(ptr), new_size);
   return reinterpret_cast<uint8_t*>(new_ptr);
 }
 
 
 class IsolateSaver {
  public:
   explicit IsolateSaver(Isolate* current_isolate)
       : saved_isolate_(current_isolate) {
     if (current_isolate != NULL) {
@@ skipping 10 matching lines @@
 
  private:
   Isolate* saved_isolate_;
 
   DISALLOW_COPY_AND_ASSIGN(IsolateSaver);
 };
 
 
 static bool PostCObjectHelper(Dart_Port port_id, Dart_CObject* message) {
   uint8_t* buffer = NULL;
-  ApiMessageWriter writer(&buffer, allocator);
+  ApiMessageWriter writer(&buffer, malloc_allocator);
   bool success = writer.WriteCMessage(message);
 
-  if (!success) return success;
+  if (!success) {
+    free(buffer);
+    return success;
+  }
 
   // Post the message at the given port.
   return PortMap::PostMessage(new Message(
       port_id, buffer, writer.BytesWritten(), Message::kNormalPriority));
 }
 
 
 DART_EXPORT bool Dart_PostCObject(Dart_Port port_id, Dart_CObject* message) {
   return PostCObjectHelper(port_id, message);
 }
@@ skipping 83 matching lines @@
   Dart_Handle result = Api::CheckAndFinalizePendingClasses(T);
   if (::Dart_IsError(result)) {
     return result;
   }
   CHECK_CALLBACK_STATE(T);
   ParseAll(T, &result);
   return result;
 }
 
 }  // namespace dart