Provide a convenience array buffer allocator

samples/shell.cc

Index: samples/shell.cc
diff --git a/samples/shell.cc b/samples/shell.cc
index ad9b1aba8bfd8b30be150bccb489f2ee31c4240f..e042815e7a7151d3b51c3e44d2a55dd03980f6e0 100644
--- a/samples/shell.cc
+++ b/samples/shell.cc
@@ -63,17 +63,6 @@ void ReportException(v8::Isolate* isolate, v8::TryCatch* handler);
 static bool run_shell;
 
 
-class ShellArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
- public:
-  virtual void* Allocate(size_t length) {
-    void* data = AllocateUninitialized(length);
-    return data == NULL ? data : memset(data, 0, length);
-  }
-  virtual void* AllocateUninitialized(size_t length) { return malloc(length); }
-  virtual void Free(void* data, size_t) { free(data); }
-};
-
-
 int main(int argc, char* argv[]) {
   v8::V8::InitializeICUDefaultLocation(argv[0]);
   v8::V8::InitializeExternalStartupData(argv[0]);
@@ -81,9 +70,9 @@ int main(int argc, char* argv[]) {
   v8::V8::InitializePlatform(platform);
   v8::V8::Initialize();
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
-  ShellArrayBufferAllocator array_buffer_allocator;
   v8::Isolate::CreateParams create_params;
-  create_params.array_buffer_allocator = &array_buffer_allocator;
+  create_params.array_buffer_allocator =
+      v8::ArrayBuffer::Allocator::NewDefaultAllocator();
   v8::Isolate* isolate = v8::Isolate::New(create_params);
   run_shell = (argc == 1);
   int result;
@@ -103,6 +92,7 @@ int main(int argc, char* argv[]) {
   v8::V8::Dispose();
   v8::V8::ShutdownPlatform();
   delete platform;
+  delete create_params.array_buffer_allocator;
   return result;
 }