Factor DartLibraryProvider out of DartLoader

sky/engine/core/script/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/core/script/dart_snapshot_loader.h"
-
-#include "base/callback.h"
-#include "base/trace_event/trace_event.h"
-#include "sky/engine/platform/weborigin/KURL.h"
-#include "sky/engine/tonic/dart_api_scope.h"
-#include "sky/engine/tonic/dart_converter.h"
-#include "sky/engine/tonic/dart_error.h"
-#include "sky/engine/tonic/dart_isolate_scope.h"
-#include "sky/engine/wtf/MainThread.h"
-
-using mojo::common::DataPipeDrainer;
-
-namespace blink {
-
-DartSnapshotLoader::DartSnapshotLoader(DartState* dart_state)
-    : dart_state_(dart_state->GetWeakPtr()) {
-}
-
-DartSnapshotLoader::~DartSnapshotLoader() {
-}
-
-void DartSnapshotLoader::LoadSnapshot(const KURL& url,
-                                      mojo::URLResponsePtr response,
-                                      const base::Closure& callback) {
-  TRACE_EVENT_ASYNC_BEGIN0("sky", "DartSnapshotLoader::LoadSnapshot", this);
-  callback_ = callback;
-
-  if (!response) {
-    fetcher_ = adoptPtr(new MojoFetcher(this, url));
-  } else {
-    OnReceivedResponse(response.Pass());
-  }
-}
-
-void DartSnapshotLoader::OnReceivedResponse(mojo::URLResponsePtr response) {
-  if (response->status_code != 200) {
-    callback_.Run();
-    return;
-  }
-  drainer_ = adoptPtr(new DataPipeDrainer(this, response->body.Pass()));
-}
-
-void DartSnapshotLoader::OnDataAvailable(const void* data, size_t num_bytes) {
-  buffer_.append(static_cast<const uint8_t*>(data), 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