Remove most usage of Vector

sky/engine/tonic/dart_snapshot_loader.cc

 // Copyright 2015 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 "sky/engine/tonic/dart_snapshot_loader.h"
 
 #include "base/callback.h"
 #include "base/trace_event/trace_event.h"
 #include "sky/engine/tonic/dart_api_scope.h"
 #include "sky/engine/tonic/dart_converter.h"
@@ skipping 14 matching lines @@
 
 void DartSnapshotLoader::LoadSnapshot(mojo::ScopedDataPipeConsumerHandle pipe,
                                       const base::Closure& callback) {
   TRACE_EVENT_ASYNC_BEGIN0("sky", "DartSnapshotLoader::LoadSnapshot", this);
 
   callback_ = callback;
   drainer_ = adoptPtr(new DataPipeDrainer(this, pipe.Pass()));
 }
 
 void DartSnapshotLoader::OnDataAvailable(const void* data, size_t num_bytes) {
-  buffer_.append(static_cast<const uint8_t*>(data), num_bytes);
+  const uint8_t* bytes = static_cast<const uint8_t*>(data);
+  buffer_.insert(buffer_.end(), bytes, bytes + num_bytes);
 }
 
 void DartSnapshotLoader::OnDataComplete() {
   TRACE_EVENT_ASYNC_END0("sky", "DartSnapshotLoader::LoadSnapshot", this);
 
   {
     DartIsolateScope scope(dart_state_->isolate());
     DartApiScope api_scope;
 
     LogIfError(Dart_LoadScriptFromSnapshot(buffer_.data(), buffer_.size()));
   }
 
   callback_.Run();
 }
 
 }  // namespace blink